Aiming at the difficulty on predicting the shielding effectiveness of high-voltage shielded cable, a simulation analysis method was studied, which is computed through the transfer impedance. The transfer impedance simulation methods for shielded cable mainly include mathematical analysis method and numerical method. This article first have studied the classical analytical model of single-braided shielded cable, and based on this, derived the analytical formula for double shielded cable with braided shield and aluminum foil. Then, according to cable transfer impedance test method - line injection method, a simulation model of the high-voltage shielded cable was established in the electromagnetic simulation software FEKO. Finally, the simulation results of analytical method and numerical method are compared to verify the accuracy of numerical modeling and simulation. Research has shown that using numerical method can effectively predict the transfer impedance of shielded cable. For the same analytical model, the numerical calculation results are completely consistent with the analytical method. By using numerical simulation method, it is possible to quickly evaluate the shielding effectiveness of cable, optimize cable parameters, and thereby reduce the optimization and testing costs of cable.