diff --git a/cmd/common.go b/cmd/common.go
index 8a73f9b0..624622fb 100644
--- a/cmd/common.go
+++ b/cmd/common.go
@@ -20,6 +20,7 @@ func Init() {
 	bootstrap.InitStreamLimit()
 	bootstrap.InitIndex()
 	bootstrap.InitUpgradePatch()
+	bootstrap.InitUsage()
 }
 
 func Release() {
diff --git a/internal/bootstrap/data/setting.go b/internal/bootstrap/data/setting.go
index 407a5c64..a9c37cf1 100644
--- a/internal/bootstrap/data/setting.go
+++ b/internal/bootstrap/data/setting.go
@@ -160,6 +160,8 @@ func InitialSettings() []model.SettingItem {
 		{Key: conf.ForwardDirectLinkParams, Value: "false", Type: conf.TypeBool, Group: model.GLOBAL},
 		{Key: conf.IgnoreDirectLinkParams, Value: "sign,alist_ts", Type: conf.TypeString, Group: model.GLOBAL},
 		{Key: conf.WebauthnLoginEnabled, Value: "false", Type: conf.TypeBool, Group: model.GLOBAL, Flag: model.PUBLIC},
+		{Key: conf.GlobalStorageSize, Value: "-1", Type: conf.TypeNumber, Group: model.GLOBAL, Flag: model.PUBLIC},
+		{Key: conf.UsageScanInterval, Value: "3600", Type: conf.TypeNumber, Group: model.GLOBAL, Flag: model.PRIVATE},
 
 		// single settings
 		{Key: conf.Token, Value: token, Type: conf.TypeString, Group: model.SINGLE, Flag: model.PRIVATE},
diff --git a/internal/bootstrap/usage.go b/internal/bootstrap/usage.go
new file mode 100644
index 00000000..527e38d5
--- /dev/null
+++ b/internal/bootstrap/usage.go
@@ -0,0 +1,12 @@
+package bootstrap
+
+import (
+	"github.com/alist-org/alist/v3/internal/usage"
+	log "github.com/sirupsen/logrus"
+)
+
+// InitUsage 初始化使用量统计
+func InitUsage() {
+	log.Info("init usage calculation")
+	usage.Init()
+}
diff --git a/internal/conf/const.go b/internal/conf/const.go
index 5cb8d850..754f303a 100644
--- a/internal/conf/const.go
+++ b/internal/conf/const.go
@@ -45,6 +45,8 @@ const (
 	ForwardDirectLinkParams = "forward_direct_link_params"
 	IgnoreDirectLinkParams  = "ignore_direct_link_params"
 	WebauthnLoginEnabled    = "webauthn_login_enabled"
+	GlobalStorageSize       = "global_storage_size"
+	UsageScanInterval       = "usage_scan_interval"
 
 	// index
 	SearchIndex     = "search_index"
diff --git a/internal/model/storage.go b/internal/model/storage.go
index e3c7e1f9..b5af4f4b 100644
--- a/internal/model/storage.go
+++ b/internal/model/storage.go
@@ -1,9 +1,71 @@
 package model
 
 import (
+	"fmt"
 	"time"
 )
 
+type Size int64
+
+func formatSize(size int64) string {
+	if size < 0 {
+		return "Unknown"
+	}
+	units := []string{"B", "KB", "MB", "GB", "TB", "PB"}
+	index := 0
+	fsize := float64(size)
+	for fsize > 1024 && index < len(units)-1 {
+		fsize /= 1024
+		index++
+	}
+	return fmt.Sprintf("%.2f %s", fsize, units[index])
+}
+
+func (s Size) String() string {
+	return formatSize(int64(s))
+}
+
+// Usage 存储使用量信息
+type Usage struct {
+	Available int64 `json:"available"`
+	Used      int64 `json:"used"`
+	Total     int64 `json:"total"`
+}
+
+// NewEmptyUsage 创建一个新的未知使用量信息（无限容量）
+func NewEmptyUsage() *Usage {
+	return &Usage{
+		Available: -1,
+		Used:      0,
+		Total:     -1,
+	}
+}
+
+// SetTotalGB 设置总容量（GB单位）
+func (u *Usage) SetTotalGB(totalGB int64) {
+	if totalGB <= 0 {
+		u.Total = -1
+		u.Available = -1
+		return
+	}
+	u.Total = totalGB * 1024 * 1024 * 1024
+	u.Available = u.Total - u.Used
+	if u.Available < 0 {
+		u.Available = 0
+	}
+}
+
+// AddUsed 增加已使用容量
+func (u *Usage) AddUsed(size int64) {
+	u.Used += size
+	if u.Total > 0 {
+		u.Available = u.Total - u.Used
+		if u.Available < 0 {
+			u.Available = 0
+		}
+	}
+}
+
 type Storage struct {
 	ID              uint      `json:"id" gorm:"primaryKey"`                        // unique key
 	MountPath       string    `json:"mount_path" gorm:"unique" binding:"required"` // must be standardized
@@ -57,3 +119,6 @@ func (p Proxy) WebdavProxy() bool {
 func (p Proxy) WebdavNative() bool {
 	return !p.Webdav302() && !p.WebdavProxy()
 }
+
+type MountedStorage struct {
+}
diff --git a/internal/search/search.go b/internal/search/search.go
index d420eb16..aad68d82 100644
--- a/internal/search/search.go
+++ b/internal/search/search.go
@@ -51,6 +51,27 @@ func Search(ctx context.Context, req model.SearchReq) ([]model.SearchNode, int64
 	return instance.Search(ctx, req)
 }
 
+// GetAllNodes 获取所有索引的节点
+func GetAllNodes(ctx context.Context) ([]model.SearchNode, error) {
+	if instance == nil {
+		return nil, errs.SearchNotAvailable
+	}
+
+	// 使用一个空白的搜索请求，获取所有文件
+	req := model.SearchReq{
+		Parent:   "",
+		Keywords: "",
+		Scope:    0, // 所有类型
+		PageReq: model.PageReq{
+			Page:    1,
+			PerPage: model.MaxInt, // 获取所有结果
+		},
+	}
+
+	nodes, _, err := instance.Search(ctx, req)
+	return nodes, err
+}
+
 func Index(ctx context.Context, parent string, obj model.Obj) error {
 	if instance == nil {
 		return errs.SearchNotAvailable
diff --git a/internal/usage/usage.go b/internal/usage/usage.go
new file mode 100644
index 00000000..4dc30b91
--- /dev/null
+++ b/internal/usage/usage.go
@@ -0,0 +1,134 @@
+package usage
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	"github.com/alist-org/alist/v3/internal/conf"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/internal/search"
+	"github.com/alist-org/alist/v3/internal/setting"
+	"github.com/alist-org/alist/v3/pkg/utils"
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	globalUsage  = model.NewEmptyUsage()
+	usageLock    = &sync.RWMutex{}
+	lastScanTime = time.Time{}
+	isScanning   = false
+	scanningLock = &sync.Mutex{}
+)
+
+// GetGlobalUsage 获取全局使用量信息
+func GetGlobalUsage() *model.Usage {
+	usageLock.RLock()
+	defer usageLock.RUnlock()
+	return globalUsage
+}
+
+// GetGlobalStorageSizeGB 获取全局存储容量（GB）
+func GetGlobalStorageSizeGB() int64 {
+	sizeStr := setting.GetStr(conf.GlobalStorageSize)
+	size, err := utils.ParseInt(sizeStr)
+	if err != nil || size <= -2 {
+		// 如果解析失败或值非法，使用默认值 -1
+		log.Warnf("invalid global storage size: %s, using default -1", sizeStr)
+		return -1
+	}
+	return size
+}
+
+// GetScanInterval 获取扫描间隔（秒）
+func GetScanInterval() int64 {
+	intervalStr := setting.GetStr(conf.UsageScanInterval)
+	interval, err := utils.ParseInt(intervalStr)
+	if err != nil || interval < 0 {
+		// 如果解析失败或值为负数，使用默认值 3600
+		log.Warnf("invalid scan interval: %s, using default 3600", intervalStr)
+		return 3600
+	}
+	return interval
+}
+
+// ScanUsageIfNeeded 如果需要则扫描使用量
+func ScanUsageIfNeeded() {
+	// 如果全局容量设置为 -1 或 0，则不扫描
+	globalSize := GetGlobalStorageSizeGB()
+	if globalSize <= 0 {
+		return
+	}
+
+	// 检查是否超过扫描间隔
+	scanInterval := GetScanInterval()
+	now := time.Now()
+
+	scanningLock.Lock()
+	if isScanning || now.Sub(lastScanTime).Seconds() < float64(scanInterval) {
+		scanningLock.Unlock()
+		return
+	}
+	isScanning = true
+	scanningLock.Unlock()
+
+	go func() {
+		defer func() {
+			scanningLock.Lock()
+			isScanning = false
+			lastScanTime = time.Now()
+			scanningLock.Unlock()
+		}()
+
+		log.Infof("start scanning usage")
+		ctx := context.Background()
+		size, err := CalculateUsage(ctx)
+		if err != nil {
+			log.Errorf("calculate usage error: %+v", err)
+			return
+		}
+
+		usageLock.Lock()
+		globalUsage.Used = size
+		globalUsage.SetTotalGB(globalSize)
+		usageLock.Unlock()
+
+		log.Infof("usage scan completed: used %s, total %s",
+			model.Size(size).String(),
+			model.Size(globalUsage.Total).String())
+	}()
+}
+
+// CalculateUsage 计算所有存储的使用量
+func CalculateUsage(ctx context.Context) (int64, error) {
+	// 使用搜索来计算总大小
+	var totalSize int64 = 0
+
+	// 获取所有文件信息
+	nodes, err := search.GetAllNodes(ctx)
+	if err != nil {
+		return 0, err
+	}
+
+	// 累计文件大小
+	for _, node := range nodes {
+		if !node.IsDir {
+			totalSize += node.Size
+		}
+	}
+
+	return totalSize, nil
+}
+
+// Init 初始化使用量模块
+func Init() {
+	globalSize := GetGlobalStorageSizeGB()
+	usageLock.Lock()
+	globalUsage.SetTotalGB(globalSize)
+	usageLock.Unlock()
+
+	// 初始进行一次扫描
+	if globalSize > 0 {
+		go ScanUsageIfNeeded()
+	}
+}
diff --git a/pkg/utils/convert.go b/pkg/utils/convert.go
new file mode 100644
index 00000000..e1e6aa0e
--- /dev/null
+++ b/pkg/utils/convert.go
@@ -0,0 +1,10 @@
+package utils
+
+import (
+	"strconv"
+)
+
+// ParseInt 将字符串解析为int64
+func ParseInt(s string) (int64, error) {
+	return strconv.ParseInt(s, 10, 64)
+}
diff --git a/server/webdav.go b/server/webdav.go
index a735e285..5e0bfc14 100644
--- a/server/webdav.go
+++ b/server/webdav.go
@@ -13,6 +13,7 @@ import (
 	"github.com/alist-org/alist/v3/internal/model"
 	"github.com/alist-org/alist/v3/internal/op"
 	"github.com/alist-org/alist/v3/internal/setting"
+	"github.com/alist-org/alist/v3/internal/usage"
 	"github.com/alist-org/alist/v3/server/webdav"
 	"github.com/gin-gonic/gin"
 	log "github.com/sirupsen/logrus"
@@ -44,6 +45,7 @@ func WebDav(dav *gin.RouterGroup) {
 }
 
 func ServeWebDAV(c *gin.Context) {
+	usage.ScanUsageIfNeeded()
 	user := c.MustGet("user").(*model.User)
 	ctx := context.WithValue(c.Request.Context(), "user", user)
 	handler.ServeHTTP(c.Writer, c.Request.WithContext(ctx))
diff --git a/server/webdav/prop.go b/server/webdav/prop.go
index a81f31b0..47f52df7 100644
--- a/server/webdav/prop.go
+++ b/server/webdav/prop.go
@@ -18,6 +18,7 @@ import (
 	"time"
 
 	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/internal/usage"
 	"github.com/alist-org/alist/v3/server/common"
 )
 
@@ -165,6 +166,14 @@ var liveProps = map[xml.Name]struct {
 		findFn: findChecksums,
 		dir:    false,
 	},
+	{Space: "DAV:", Local: "quota-available-bytes"}: {
+		findFn: findQuotaAvailable,
+		dir:    true,
+	},
+	{Space: "DAV:", Local: "quota-used-bytes"}: {
+		findFn: findQuotaUsed,
+		dir:    true,
+	},
 }
 
 // TODO(nigeltao) merge props and allprop?
@@ -496,3 +505,18 @@ func findChecksums(ctx context.Context, ls LockSystem, name string, fi model.Obj
 	}
 	return checksums, nil
 }
+
+func findQuotaAvailable(ctx context.Context, ls LockSystem, name string, fi model.Obj) (string, error) {
+	globalUsage := usage.GetGlobalUsage()
+	if globalUsage.Available < 0 {
+		// 如果是无限空间，返回一个大数值
+		return "9223372036854775807", nil // maxInt64
+	}
+
+	return strconv.FormatInt(globalUsage.Available, 10), nil
+}
+
+func findQuotaUsed(ctx context.Context, ls LockSystem, name string, fi model.Obj) (string, error) {
+	globalUsage := usage.GetGlobalUsage()
+	return strconv.FormatInt(globalUsage.Used, 10), nil
+}