The adhesive force between microsurfaces is very important to microelectric mechanical system (MEMS), being always a key factor that detemines the energy dissipation and even the life span. In MEMS, the meniscus force mainly depends on the meniscus shape formed between the contact surfaces. This paper analyzes the meniscus shape changes during the seperation of two microsurfaces. Different meniscus shapes were obtained as a result of different hydrophilic/hydrophobic properties, initial liquid heights and separate distances and so on. The fracture height, the meniscus force value and their change rules in different initial conditions are obtained by numerical simulation, which provides a basis of the MEMS performance analysis and life span calculation.