Interior permanent magnet synchronous motor (IPMSM) is widely used in the electric vehicle field due to its high torque-to-current ratio, wider speed regulation range, high power density, and high efficiency. IPMSM for electric vehicles has a complicated magnetic circuit structure and a high degree of saturation, causing the cross coupling between the magnetic circuits of quadrature- and direct-axis. Therefore, mutual inductance is generated between quadrature and direct axis. Magnetic circuits analysis is carried out for the cross-coupling phenomenon, and the influences of cross coupling on the magnetic flux linkage and inductance parameters are elaborated. The frozen permeability method (FPM) and the finite element method (FEM) are used to calculate the quadrature- and direct-axis inductances, and the changes of inductance parameters with current are quantitatively analyzed. The two calculation methods are compared, and it is found that the calculation results agree well with each other. The advantages and disadvantages of the two methods for calculating the quadrature- and direct-axis inductance are analyzed. The analysis shows that using FEM as the main means and FPM as the auxiliary to calculate the quadrature- and direct-axis inductance parameters, the accuracy of the inductance parameters can be ensured and the calculation time can be shortened.