Pure 3D elastic wave numerical simulations require huge computation resources, which is not conducive to scientific research when computer configuration is not high. 2D elastic wave numerical simulation cannot accurately represent 3D situation, and the simulation results are relatively unsatisfactory by using the traditional 3D pseudo spectral method when the model and spatial distribution of wave field are complex. Thus, based on high accurate oneorder elastic wave equation expressed with velocity and stress, this paper uses 2.5D numerical simulation method to calculate the partial derivatives of yspatial orientation by Fourier transforming and the partial derivative of x, y spatial orientation and time domain by finite difference. This method can hence compute the 3D elastic wave field in 2D media. This paper also simulates the multiwave wave field in anisotropy media using 2.5D numerical simulation method, which shows that the 2.5D numerical simulation method is an efficient and accurate forward method. This method can also be adapted to complex models. Through wave field analysis, the authors further understand the propagation law of the seismic wave in anisotropy media.