非饱和带地下水运动实质上是一个水气二相渗流过程。本文以多相渗流理论为基础，从水气二相渗流的连续性方程和达西定律出发，推导了非饱和带水气二相渗流的耦合动力学模型，讨论了模型的ＩＭＰＥＳ和全隐式联立求解方法的原理和步骤，认为ＩＭＰＥＳ求解方法由于达西系数项的处理，饱和度的计算均采用显式，因此该解法具有稳定性差、精度低且要求计算时间步长小的局限性；而全隐式联立求解方法是联立求解气相、水相方程，同时求出压力和饱和度值，因此压力和饱和度值都是隐式求出，具有较高精度，且无条件稳定，应是今后模型求解的重点研究内容 Unsaturated groundwater movement is essentially a two-phase water and gas seepage process. Based on the theory of multiphase seepage, this paper deduces the coupling dynamics model of unsaturated gas-water two-phase seepage based on the continuity equation and Darcy’s law of the two-phase seepage flow, and discusses the IMPES and the total implicit Because of the processing of Darcy coefficient and the calculation of saturation are all explicit, the solution of IMPES has some limitations, such as poor stability, low precision and small computation time step. The total implicit simultaneous solution method is to solve the gas phase and water phase equations simultaneously and calculate the pressure and saturation values ​​simultaneously. Therefore, the pressure and saturation values ​​are implicitly determined, with high precision and unconditionally stable. It is the key research content of the model solution in the future