The alternating direction implicit (ADI) scheme is used for the parabolic equation (PE) method to analyse electromagnetic scattering problems. The three-dimensional (3D) electromagnetic scattering problem can be reduced to a series of 1D problems to be solved by the ADI-PE method, which is more efficient than the traditional Crank-Nicolson scheme. In this way, both the memory requirement and the central processing unit time can be saved substantially even for electrically large targets with encouraging accuracy. The full bistatic scattering pattern can be obtained by decoupling the marching direction from the direction of the incidence wave. Numerical results are provided to demonstrate the efficiency of the proposed method.