中文说明：
本章先分析说明伪谱法求解波动方程的算法原理，再给出弹性波场伪谱法数值模拟的改进算法；然后，通过直接引入P波波场变量和S波波场变量，给出可实现弹性波场的P波和S波分解的波动方程，并用伪谱法实现弹性波场的P波和S波分解的数值模拟；最后用伪谱法对井间地震的复杂波场作数值模拟，分析井间地震波场中各种波的传播规律。
English Description：
In this chapter, the algorithm principle of pseudo spectral method for solving wave equation is analyzed firstly, and then the improved algorithm of pseudo spectral method for numerical simulation of elastic wave field is given. Then, by directly introducing P-wave field variable and S-wave field variable, the wave equation which can realize P-wave and S-wave decomposition of elastic wave field is given, and the pseudo spectral method is used to realize the numerical simulation of P-wave and S-wave decomposition of elastic wave field. Finally, the pseudo spectral method is used The complex wave field of crosswell seismic is numerically simulated, and the propagation law of various waves in crosswell seismic wave field is analyzed.