本文计算了含有高速夹层介质中首波的理论地震图。通过分析得到,当高速夹层薄到一定程度时,就会产生干涉型首波,从而从一个侧面证明了射线理论的局限性。通过对地震波反射—折射系数能量守恒关系的分析,探讨了反射—折射系数大于1的可能性。最后,介绍了一种计算垂向不均匀介质中拉梅问题理论地震图的数值方法——有限差分法。 In this paper, the theoretical seismograms of the first wave in high-speed interlayer media are calculated. The analysis shows that when the high-speed sandwich thin to a certain extent, it will produce the interference of the first wave, which proved from one side of the limitations of ray theory. Based on the analysis of the energy conservation of reflection / refraction index of seismic wave, the possibility of reflection-refraction coefficient greater than 1 is discussed. Finally, a numerical method of finite difference method for calculating the theoretical map of Lame problem in vertical inhomogeneous media is introduced.