diff --git a/model/dto/video/video_caption_dto.go b/model/dto/video/video_caption_dto.go
index d2e1dc2..ee36cf0 100644
--- a/model/dto/video/video_caption_dto.go
+++ b/model/dto/video/video_caption_dto.go
@@ -32,12 +32,12 @@ type SubtitleSegment struct {
 
 // SubtitleStyle 字幕样式配置
 type SubtitleStyle struct {
-	FontSize  int      `json:"fontSize" d:"28" dc:"字号(默认28)"`
+	FontSize  int      `json:"fontSize" d:"48" dc:"字号(默认48)"`
 	FontColor string   `json:"fontColor" d:"#FFFFFF" dc:"字体颜色(默认白色)"`
 	BgColor   *string  `json:"bgColor" dc:"背景色,空字符串=透明(默认#000000)。传空字符串 '' 可去掉背景色"`
-	BgOpacity *float64 `json:"bgOpacity" dc:"背景透明度0-1(默认0.6)。传0可使背景完全透明"`
+	BgOpacity *float64 `json:"bgOpacity" dc:"背景透明度0-1(默认0.4)。传0可使背景完全透明"`
 	X         string   `json:"x" d:"center" dc:"水平位置:left/center/right或像素值(默认center)"`
-	Y         string   `json:"y" d:"bottom" dc:"垂直位置:top/center/bottom或像素值(默认bottom)"`
+	Y         string   `json:"y" d:"65%" dc:"垂直位置:top/center/bottom或像素值或百分比(默认65%)"`
 }
 
 // ---------- 创建字幕任务 ----------
diff --git a/service/video/caption_service.go b/service/video/caption_service.go
index 0376475..e2ab6e4 100644
--- a/service/video/caption_service.go
+++ b/service/video/caption_service.go
@@ -726,10 +726,10 @@ func hexToRGBA(hex string, alpha float64) string {
 // subtitlesToElements 将外部传入的字幕时间线转为底部字幕元素
 func subtitlesToElements(subtitles []dto.SubtitleSegment, style *dto.SubtitleStyle) []dto.CaptionElement {
 	// 应用默认值
-	fontSize := 28
+	fontSize := 48
 	fontColor := "#FFFFFF"
 	bgColor := "#000000"
-	bgOpacity := 0.6
+	bgOpacity := 0.4
 	if style != nil {
 		if style.FontSize > 0 {
 			fontSize = style.FontSize
@@ -750,7 +750,7 @@ func subtitlesToElements(subtitles []dto.SubtitleSegment, style *dto.SubtitleSty
 
 	// 从样式配置中读取字幕位置
 	subtitleX := "center"
-	subtitleY := "bottom"
+	subtitleY := "65%"
 	if style != nil {
 		if style.X != "" {
 			subtitleX = style.X