diff --git a/lib/potential/mkernel_tricone.cpp b/lib/potential/mkernel_tricone.cpp
index 556429b..557b6c3 100644
--- a/lib/potential/mkernel_tricone.cpp
+++ b/lib/potential/mkernel_tricone.cpp
@@ -169,7 +169,9 @@ gctl::point3dc gctl::magkernel_single(const mag_tricone &a_ele, const point3ds &
 	// nT -> T 1e-9 / 4*pi*e-7 = 1/(400*pi)*100 = 1/(4*pi) -> A/m
 	gctl::tensor gt = -1.0/(4.0*GCTL_Pi)*(face_sum - edge_sum);
 	gctl::point3dc out_c = R*(gt*gp->B);
-	out_c.x *= -1.0;
+	out_c.x *= -1.0; // x对应半径向分量
+	out_c.y *= -1.0; // y对应纬向分量
+	// z对应经向分量
 	return out_c;
 }