diff --git a/src/models/mod.rs b/src/models/mod.rs
index 4d54b91..fa0c7e8 100644
--- a/src/models/mod.rs
+++ b/src/models/mod.rs
@@ -9,3 +9,5 @@ pub mod comment;
 pub mod post;
 /// 用户模型、用户角色与可公开用户信息。
 pub mod user;
+/// 回收站与站点配置模型。
+pub mod settings;
diff --git a/src/models/settings.rs b/src/models/settings.rs
new file mode 100644
index 0000000..d04a417
--- /dev/null
+++ b/src/models/settings.rs
@@ -0,0 +1,71 @@
+//! 回收站与站点配置模型。
+
+/// 默认保留天数（天）。
+pub const DEFAULT_RETENTION_DAYS: i32 = 30;
+/// 默认不启用自动清理。
+pub const DEFAULT_AUTO_PURGE_ENABLED: bool = false;
+/// 保留天数下限（天）。
+pub const MIN_RETENTION_DAYS: i32 = 1;
+/// 保留天数上限（天）。防止误填超大值导致永不清理。
+pub const MAX_RETENTION_DAYS: i32 = 365;
+
+/// 回收站配置。
+#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+pub struct TrashSettings {
+    /// 是否启用自动定时清理。
+    pub auto_purge_enabled: bool,
+    /// 已删除文章保留天数，超过后被后台任务物理删除。
+    pub retention_days: i32,
+}
+
+impl Default for TrashSettings {
+    fn default() -> Self {
+        Self {
+            auto_purge_enabled: DEFAULT_AUTO_PURGE_ENABLED,
+            retention_days: DEFAULT_RETENTION_DAYS,
+        }
+    }
+}
+
+impl TrashSettings {
+    /// 将保留天数钳制到合法范围 [MIN, MAX]。
+    pub fn clamp_retention(days: i32) -> i32 {
+        days.clamp(MIN_RETENTION_DAYS, MAX_RETENTION_DAYS)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_is_disabled_30_days() {
+        let s = TrashSettings::default();
+        assert!(!s.auto_purge_enabled);
+        assert_eq!(s.retention_days, 30);
+    }
+
+    #[test]
+    fn clamp_retention_keeps_valid() {
+        assert_eq!(TrashSettings::clamp_retention(7), 7);
+        assert_eq!(TrashSettings::clamp_retention(30), 30);
+    }
+
+    #[test]
+    fn clamp_retention_clamps_below_min() {
+        assert_eq!(TrashSettings::clamp_retention(0), MIN_RETENTION_DAYS);
+        assert_eq!(TrashSettings::clamp_retention(-5), MIN_RETENTION_DAYS);
+    }
+
+    #[test]
+    fn clamp_retention_clamps_above_max() {
+        assert_eq!(TrashSettings::clamp_retention(366), MAX_RETENTION_DAYS);
+        assert_eq!(TrashSettings::clamp_retention(i32::MAX), MAX_RETENTION_DAYS);
+    }
+
+    #[test]
+    fn clamp_retention_boundary() {
+        assert_eq!(TrashSettings::clamp_retention(MIN_RETENTION_DAYS), MIN_RETENTION_DAYS);
+        assert_eq!(TrashSettings::clamp_retention(MAX_RETENTION_DAYS), MAX_RETENTION_DAYS);
+    }
+}