diff --git a/AstroLib/Include/AsAttitudeParam_2023.h b/AstroLib/Include/AsAttitudeParam_2023.h
index e58f7934e795f8ee45e68effdc84e137123c8294..771845069ca38337f09068e81ee65150f92611e7 100644
--- a/AstroLib/Include/AsAttitudeParam_2023.h
+++ b/AstroLib/Include/AsAttitudeParam_2023.h
@@ -3,6 +3,7 @@
 #include "AsCoordinate.h"
 #include "AsMath.h"
 #include "AsAttitudeParam.h"
+#include "AstroLib.h"
 
 ///***********************************************************************
 /// The conversion from matrix to axis and angle.
@@ -15,4 +16,18 @@
 /// @Param	angle	旋转角[0, pi]
 ///***********************************************************************
 void AsMtxToAxAng(const CMatrix<double>& mtx,
-	CCoord& axis, double& angle);
\ No newline at end of file
+	CCoord& axis, double& angle);
+
+
+///***********************************************************************
+/// 方向余弦阵转321转序欧拉角
+/// @Author	Li Sibei
+/// @Date	2023.04.06
+/// @Input
+/// @Param	mtx		方向余弦阵
+/// @Output
+/// @Param	euler	欧拉角
+///***********************************************************************
+void AsMtxToEuler321(
+	const CMatrix<double>& mtx, 
+	CEuler& euler);
\ No newline at end of file
diff --git a/AstroLib/Src/AsAttitudeParam_2023.cpp b/AstroLib/Src/AsAttitudeParam_2023.cpp
index f54421b8475fb3470523b283c9576906185a8450..4e1341e4b4c3b3fe07a6e6578cf6fbd5c2d76636 100644
--- a/AstroLib/Src/AsAttitudeParam_2023.cpp
+++ b/AstroLib/Src/AsAttitudeParam_2023.cpp
@@ -1,6 +1,7 @@
 #include "AsCoordinate.h"
 #include "AsMath.h"
 #include "AsAttitudeParam.h"
+#include "AstroLib.h"
 
 ///***********************************************************************
 /// The conversion from matrix to axis and angle.
@@ -24,8 +25,8 @@ void AsMtxToAxAng(const CMatrix<double>& mtx,
 	double p4 = mm[0][0] * mm[0][0] + mm[1][0] * mm[1][0] + mm[2][0] * mm[2][0];
 	double p5 = mm[0][1] * mm[0][1] + mm[1][1] * mm[1][1] + mm[2][1] * mm[2][1];
 	double p6 = mm[0][2] * mm[0][2] + mm[1][2] * mm[1][2] + mm[2][2] * mm[2][2];
-	if (!(abs(p1)<1e-9 && abs(p2)<1e-9 && abs(p3)<1e-9 && 
-		  abs(p4-1)<1e-9 && abs(p5 - 1)<1e-9 && abs(p6 - 1)<1e-9) ){
+	if (!(abs(p1)<1e-9 && abs(p2)<1e-9 && abs(p3)<1e-9 &&
+		abs(p4 - 1)<1e-9 && abs(p5 - 1)<1e-9 && abs(p6 - 1)<1e-9)) {
 		printf("warning! not Orthogonal Matrix\n");
 		angle = 0;
 		axis[0] = 0;
@@ -88,4 +89,56 @@ void AsMtxToAxAng(const CMatrix<double>& mtx,
 		axis[1] = 0;
 		axis[2] = 0;
 	}
+}
+
+
+///***********************************************************************
+/// 方向余弦阵转为321转序欧拉角
+/// @Author	Li Sibei
+/// @Date	2023.04.06
+/// @Input
+/// @Param	mtx	    坐标转换矩阵
+/// @Output
+/// @Param	angle	欧拉角
+///***********************************************************************
+void AsMtxToEuler321(const CMatrix<double>& mtx, CEuler& euler)
+{
+	/*异常数据处理1：输入非正交矩阵*/
+	CMatrix<double> MTX1(mtx);
+	CMatrix<double> mtx1 = MTX1.Transpose();
+	CMatrix<double> mtx2 = MTX1.Inv();
+	CMatrix<double> mtx3 = mtx1 - mtx2;
+	for (int i = 0; i <= 2; i++)
+	{
+		for (int j = 0; j <= 2; j++)
+		{
+			if (mtx3[i][j] > 1e-15 || mtx3[i][j] < -1e-15)
+			{
+				printf("Error: 方向余弦阵非正交矩阵!\n");
+				return;
+			}
+		}
+	}
+	/*异常数据处理2：奇异*/
+	if (mtx[0][2] == 1)
+	{
+		euler.m_Angle1 = -atan2(mtx[2][1], mtx[1][1]);
+		euler.m_Angle2 = -asin(mtx[0][2]);
+		euler.m_Angle3 = 0;
+		return;
+	}
+	else if (mtx[0][2] == -1)
+	{
+		euler.m_Angle1 = atan2(mtx[2][1], mtx[1][1]);
+		euler.m_Angle2 = -asin(mtx[0][2]);
+		euler.m_Angle3 = 0;
+		return;
+	}
+	/*一般情况求解*/
+	else
+	{
+		euler.m_Angle1 = atan2(mtx[0][1], mtx[0][0]);
+		euler.m_Angle2 = -asin(mtx[0][2]);
+		euler.m_Angle3 = atan2(mtx[1][2], mtx[2][2]);
+	}
 }
\ No newline at end of file