diff --git a/config.example.yaml b/config.example.yaml
index e3f9014c..046bba34 100644
--- a/config.example.yaml
+++ b/config.example.yaml
@@ -31,7 +31,7 @@ database:
   max_open_conn: 128
   conn_max_lifetime: 1800
   conn_max_idle_time: 600
-  log_level: "info"            # error | warn | info | debug | silent
+  log_level: "info"            # error | warn | info | debug | silent；SQL 语句仅在 log.level=debug 时输出
   ssl_mode: "disable"
   time_zone: "UTC"
   application_name: "wavelet-server"
diff --git a/internal/db/postgres_logger.go b/internal/db/postgres_logger.go
index eb7964d9..0bfd0f7a 100644
--- a/internal/db/postgres_logger.go
+++ b/internal/db/postgres_logger.go
@@ -53,30 +53,25 @@ func (l *gormZapLogger) Trace(ctx context.Context, begin time.Time, fc func() (s
 	elapsed := time.Since(begin)
 	switch {
 	case err != nil && l.logLevel >= gormLogger.Error && (!errors.Is(err, gorm.ErrRecordNotFound) || !l.ignoreRecordNotFoundError):
-		sql, rows := fc()
-		if rows == -1 {
-			logger.ErrorF(ctx, "%s\n[%.3fms] [rows:%v] %s", err, float64(elapsed.Nanoseconds())/nanoToMilli, "-", sql)
-		} else {
-			logger.ErrorF(ctx, "%s\n[%.3fms] [rows:%v] %s", err, float64(elapsed.Nanoseconds())/nanoToMilli, rows, sql)
-		}
+		_, rows := fc()
+		logger.ErrorF(ctx, "database query failed: %s [%.3fms] [rows:%v]", err, float64(elapsed.Nanoseconds())/nanoToMilli, formatRows(rows))
 	case elapsed > l.slowThreshold && l.slowThreshold != 0 && l.logLevel >= gormLogger.Warn:
-		sql, rows := fc()
+		_, rows := fc()
 		slowLog := fmt.Sprintf("SLOW SQL >= %v", l.slowThreshold)
-		if rows == -1 {
-			logger.WarnF(ctx, "%s\n[%.3fms] [rows:%v] %s", slowLog, float64(elapsed.Nanoseconds())/nanoToMilli, "-", sql)
-		} else {
-			logger.WarnF(ctx, "%s\n[%.3fms] [rows:%v] %s", slowLog, float64(elapsed.Nanoseconds())/nanoToMilli, rows, sql)
-		}
+		logger.WarnF(ctx, "%s [%.3fms] [rows:%v]", slowLog, float64(elapsed.Nanoseconds())/nanoToMilli, formatRows(rows))
 	case l.logLevel == gormLogger.Info:
 		sql, rows := fc()
-		if rows == -1 {
-			logger.InfoF(ctx, "[%.3fms] [rows:%v] %s", float64(elapsed.Nanoseconds())/nanoToMilli, "-", sql)
-		} else {
-			logger.InfoF(ctx, "[%.3fms] [rows:%v] %s", float64(elapsed.Nanoseconds())/nanoToMilli, rows, sql)
-		}
+		logger.DebugF(ctx, "[%.3fms] [rows:%v] %s", float64(elapsed.Nanoseconds())/nanoToMilli, formatRows(rows), sql)
 	}
 }
 
+func formatRows(rows int64) interface{} {
+	if rows == -1 {
+		return "-"
+	}
+	return rows
+}
+
 func parseLogLevel(level string) gormLogger.LogLevel {
 	level = strings.ToLower(level)
 	switch level {
@@ -88,6 +83,8 @@ func parseLogLevel(level string) gormLogger.LogLevel {
 		return gormLogger.Warn
 	case "info":
 		return gormLogger.Info
+	case "debug":
+		return gormLogger.Info
 	default:
 		return gormLogger.Info
 	}
diff --git a/internal/db/postgres_logger_test.go b/internal/db/postgres_logger_test.go
new file mode 100644
index 00000000..20539a5b
--- /dev/null
+++ b/internal/db/postgres_logger_test.go
@@ -0,0 +1,39 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package db
+
+import (
+	"testing"
+
+	gormLogger "gorm.io/gorm/logger"
+)
+
+func TestParseLogLevel(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name            string
+		configuredLevel string
+		want            gormLogger.LogLevel
+	}{
+		{
+			name:            "debug enables SQL trace processing",
+			configuredLevel: "debug",
+			want:            gormLogger.Info,
+		},
+		{
+			name:            "development preserves configured level",
+			configuredLevel: "warn",
+			want:            gormLogger.Warn,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := parseLogLevel(tt.configuredLevel); got != tt.want {
+				t.Fatalf("parseLogLevel() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}