diff --git a/internal/raycast/raycast.go b/internal/raycast/raycast.go
index e8b79fee..8a49236b 100644
--- a/internal/raycast/raycast.go
+++ b/internal/raycast/raycast.go
@@ -48,8 +48,8 @@ func Cast(origin, dir [3]float64, maxDist float64, solid Solid) (Hit, bool) {
 	dist := 0.0
 	for dist <= maxDist {
 		if solid(x, y, z) {
-			// 当前格命中：面法线 = 上一步进入方向
-			return Hit{X: x, Y: y, Z: z, Face: face, Prev: [3]int32{x - face[0], y - face[1], z - face[2]}, Dist: dist}, true
+			// 当前格命中：面法线指向射线来向（背离方块），放置位 = 命中格 + 面法线
+			return Hit{X: x, Y: y, Z: z, Face: face, Prev: [3]int32{x + face[0], y + face[1], z + face[2]}, Dist: dist}, true
 		}
 		// 选择 tMax 最小的轴步进
 		switch {