Based on porous medium theory, used separation of variables, the longitudinal vibration of soil is solved by seeing soil as transversely isotropic saturated porous medium, and established the control equations of longitudinal vibration of saturated soil layer. The solution of the vertical vibration of the pile in transversely isotropic saturated is obtained by considering the continuous conditions at the soil-pile and the orthogonality of trigonometric functions, and also analyzed the effect of parameters on vertical vibration of the pile. The results indicate that there is resonance for pile-soil system, and the frequency has great effect on complex stiffness, the peak of complex stiffness decreases as the anisotropy parameter is increased.