When I import the".dat"or".iges"files into the autogrid,the system will send out message"Discontinuity of 180 degrees in leading edge",What's wrong with this problem?

I suppose it has to do with the orientation of the geometry definition you are using. - Error messages of Numeca Products some times are not that clear. ...

Can you please give a closer specification of your input data !?

latest versions check the geometry when you link it to the mesh project... in this case all meridional curves are subject to an angle deviation check basically to try to identify loops in the curve, which will be impossible to mesh. With 180 degrees, your curve has a loop, most likely...