diff --git a/internal/expiry/model.go b/internal/expiry/model.go
index 2fe889d..02429d2 100644
--- a/internal/expiry/model.go
+++ b/internal/expiry/model.go
@@ -1,19 +1,91 @@
 package expiry
 
-import "time"
+import (
+	"time"
 
-// ExpiryItem 表示保质期物品。
-// 详细字段会在后续 issue 中完善。
+	"gorm.io/gorm"
+)
+
+const (
+	// 物品分类
+	CategoryFood     = "food"
+	CategoryMedicine = "medicine"
+	CategoryCosmetic = "cosmetic"
+	CategoryOther    = "other"
+)
+
+const (
+	// 物品状态
+	StatusNormal    = "normal"
+	StatusExpiring  = "expiring"
+	StatusExpired   = "expired"
+	StatusUsed      = "used"
+	StatusDiscarded = "discarded"
+)
+
+var defaultRemindDays = []int{7, 3, 1}
+
+// ExpiryItem 表示保质期物品数据模型。
 type ExpiryItem struct {
-	ID        uint      `json:"id"`
-	CreatedAt time.Time `json:"created_at"`
-	UpdatedAt time.Time `json:"updated_at"`
+	ID             uint           `json:"id" gorm:"primaryKey;comment:主键ID"`
+	UserID         uint           `json:"user_id" gorm:"not null;index:idx_user_expiry,priority:1;index:idx_user_category,priority:1;index:idx_user_status,priority:1;comment:用户ID"`
+	MiniProgramID  uint           `json:"mini_program_id" gorm:"not null;comment:小程序ID"`
+	Name           string         `json:"name" gorm:"size:100;not null;comment:物品名称"`
+	Category       string         `json:"category" gorm:"size:20;not null;index:idx_user_category,priority:2;comment:分类"`
+	ProductionDate *time.Time     `json:"production_date" gorm:"type:date;comment:生产日期"`
+	ExpiryDate     time.Time      `json:"expiry_date" gorm:"type:date;not null;index:idx_user_expiry,priority:2;comment:过期日期"`
+	ShelfLifeDays  *int           `json:"shelf_life_days" gorm:"comment:保质期天数"`
+	Quantity       int            `json:"quantity" gorm:"default:1;comment:数量"`
+	Location       string         `json:"location" gorm:"size:50;comment:存放位置"`
+	Remark         string         `json:"remark" gorm:"size:255;comment:备注"`
+	Status         string         `json:"status" gorm:"size:20;default:'normal';index:idx_user_status,priority:2;comment:状态"`
+	CreatedAt      time.Time      `json:"created_at" gorm:"comment:创建时间"`
+	UpdatedAt      time.Time      `json:"updated_at" gorm:"comment:更新时间"`
+	DeletedAt      gorm.DeletedAt `json:"-" gorm:"index:idx_deleted_at;comment:删除时间"`
+}
+
+func (ExpiryItem) TableName() string {
+	return "expiry_items"
+}
+
+// CalculateDaysLeft 计算当前日期与过期日期之间的天数差。
+func (item *ExpiryItem) CalculateDaysLeft() int {
+	now := dateOnly(time.Now())
+	expiry := dateOnly(item.ExpiryDate)
+	return int(expiry.Sub(now).Hours() / 24)
+}
+
+// CalculateStatus 根据过期日期动态计算状态。
+// 若已被业务标记为 used/discarded，则保留该状态。
+func (item *ExpiryItem) CalculateStatus() string {
+	if item.Status == StatusUsed || item.Status == StatusDiscarded {
+		return item.Status
+	}
+
+	daysLeft := item.CalculateDaysLeft()
+	if daysLeft < 0 {
+		return StatusExpired
+	}
+	if daysLeft <= 7 {
+		return StatusExpiring
+	}
+	return StatusNormal
 }
 
 // ExpiryUserSettings 表示用户提醒设置。
-// 详细字段会在后续 issue 中完善。
 type ExpiryUserSettings struct {
-	ID        uint      `json:"id"`
-	CreatedAt time.Time `json:"created_at"`
-	UpdatedAt time.Time `json:"updated_at"`
+	ID         uint      `json:"id" gorm:"primaryKey;comment:主键ID"`
+	UserID     uint      `json:"user_id" gorm:"not null;uniqueIndex;comment:用户ID"`
+	RemindDays []int     `json:"remind_days" gorm:"type:json;serializer:json;comment:提醒天数"`
+	CreatedAt  time.Time `json:"created_at" gorm:"comment:创建时间"`
+	UpdatedAt  time.Time `json:"updated_at" gorm:"comment:更新时间"`
+}
+
+func (ExpiryUserSettings) TableName() string {
+	return "expiry_user_settings"
+}
+
+func dateOnly(t time.Time) time.Time {
+	year, month, day := t.In(time.Local).Date()
+	return time.Date(year, month, day, 0, 0, 0, 0, time.Local)
 }
diff --git a/internal/expiry/model_test.go b/internal/expiry/model_test.go
new file mode 100644
index 0000000..a1e1e9c
--- /dev/null
+++ b/internal/expiry/model_test.go
@@ -0,0 +1,80 @@
+package expiry
+
+import (
+	"testing"
+	"time"
+)
+
+func TestCalculateDaysLeft(t *testing.T) {
+	base := dateOnly(time.Now())
+	item := &ExpiryItem{
+		ExpiryDate: base.AddDate(0, 0, 5),
+	}
+
+	if daysLeft := item.CalculateDaysLeft(); daysLeft != 5 {
+		t.Fatalf("expected daysLeft=5, got %d", daysLeft)
+	}
+}
+
+func TestCalculateStatus(t *testing.T) {
+	base := dateOnly(time.Now())
+	tests := []struct {
+		name       string
+		item       ExpiryItem
+		wantStatus string
+	}{
+		{
+			name: "已过期",
+			item: ExpiryItem{
+				ExpiryDate: base.AddDate(0, 0, -1),
+			},
+			wantStatus: StatusExpired,
+		},
+		{
+			name: "今天过期",
+			item: ExpiryItem{
+				ExpiryDate: base,
+			},
+			wantStatus: StatusExpiring,
+		},
+		{
+			name: "7天内即将过期",
+			item: ExpiryItem{
+				ExpiryDate: base.AddDate(0, 0, 7),
+			},
+			wantStatus: StatusExpiring,
+		},
+		{
+			name: "正常状态",
+			item: ExpiryItem{
+				ExpiryDate: base.AddDate(0, 0, 8),
+			},
+			wantStatus: StatusNormal,
+		},
+		{
+			name: "保留已使用状态",
+			item: ExpiryItem{
+				ExpiryDate: base.AddDate(0, 0, -10),
+				Status:     StatusUsed,
+			},
+			wantStatus: StatusUsed,
+		},
+		{
+			name: "保留已丢弃状态",
+			item: ExpiryItem{
+				ExpiryDate: base.AddDate(0, 0, -10),
+				Status:     StatusDiscarded,
+			},
+			wantStatus: StatusDiscarded,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := tt.item.CalculateStatus()
+			if got != tt.wantStatus {
+				t.Fatalf("expected status=%s, got %s", tt.wantStatus, got)
+			}
+		})
+	}
+}