Dim StartTan(0 To 2) As Double
Dim EndTan(0 To 2) As Double

StartTan(0) = 1
StartTan(1) = 2
StartTan(2) = 3

EndTan(0) = 47
EndTan(1) = 58
EndTan(2) = 69

Dim SzXiePaoDianYiwei(302) As Single
Dim I As Integer
Dim K As Integer
For I = 0 To 302
    SzXiePaoDianYiwei(I) = 10 * I + 1
Next
Dim Splineboj As AcadSpline
Set Splineboj = Acadapp.ActiveDocument.ModelSpace.AddSpline(SzXiePaoDianYiwei, StartTan, EndTan)

没有装CAD，无法详细测试，但是查了一些示例代码，没有明显的错误。
可能是数据的问题，建议详细查一下
SzXiePaoDianYiwei(3*n)，SzXiePaoDianYiwei(3*n+1)， SzXiePaoDianYiwei(3*n+2)  分别对应是X、Y、Z，楼主这段代码不知道是否可以正常画出东西来
For I = 0 To 302
    SzXiePaoDianYiwei(I) = 10 * I + 1
Next

感谢您的及时回复，我找到原因了是引用那里CAD的版本选择错了。