diff --git a/src/widgets/render/exterior/mod.rs b/src/widgets/render/exterior/mod.rs
index 60216a4..3dcd86e 100644
--- a/src/widgets/render/exterior/mod.rs
+++ b/src/widgets/render/exterior/mod.rs
@@ -3,6 +3,7 @@ use super::super::Render;
 use crate::coords::Range;
 use femtovg::{renderer::OpenGl, Canvas, Color, Paint, Path};
 use glib::subclass::types::ObjectSubclassIsExt;
+use gtk::prelude::*;
 
 glib::wrapper! {
     pub struct ExteriorWidget(ObjectSubclass<imp::ExteriorWidget>);
@@ -53,7 +54,8 @@ impl ExteriorWidget {
         let lon_keypoints = lon_range.key_points(10);
         let lat_keypoints = lat_range.key_points(5);
         let mut paint = Paint::color(Color::white()); // 黑色字体
-        paint.set_font_size(25.0);
+        let dpi = render.scale_factor();
+        paint.set_font_size((dpi * 12) as f32);
 
         for lon in lon_keypoints.iter() {
             let (x, _) = render.map((*lon, lat_range.0)).unwrap();