利用离散单元法模拟岩土体水力耦合行为时，有必要考虑块体的渗透性。为此，基于流量守恒原理，建立了块体间三种接触变化导致的边界节点水头变化关系，它们与 Ｃｕｎｄａｌｌ已建立的边界节点质量和速度变化关系一起，使二维离散单元法模拟岩土体水力耦合行为时满足力学的基本原理。 When using discrete element method to simulate the hydraulic coupling behavior of rock and soil, it is necessary to consider the permeability of the block. For this reason, based on the principle of flow conservation, the relationships between the head and head changes of the boundary nodes caused by three kinds of contact changes among the blocks are established, and together with the relationship between the quality and the velocity of the boundary nodes established by Cundall, the two-dimensional discrete element method Hydraulically Coupled Behavior to Meet the Fundamentals of Mechanics.