Abstract: In the stability analysis of rock engineering, the stiffness coefficient of fractures is a vital mechanical parameter that is related to the accuracy and reliability of the calculation and analysis. At the same time, it is still a tricky task to obtain the stiffness coefficient of fractures. When the stress wave propagates to the fracture in the rock mass, reflection and transmission phenomena can occur, which are closely related to the stiffness coefficient of fractures. The transmission coefficient of the stress wave can be employed to invert the dynamic stiffness coefficient of fracture. In this paper, based on the particle discrete element method, a piecewise linear contact model and an absorption boundary model of stress waves are developed, and a series of simulation of stress wave propagation in the macroscopic rock mass is carried out. The static and dynamic stiffness coefficients of the fracture are separately calculated according to its stress-deformation curve under the quasi-static compression test simulation and stress wave transmission coefficient. The simulation results show that: (1)The piecewise linear contact model developed by C++language is well used to simulate the nonlinear deformation characteristics of the fracture; (2)The particle discrete element method can accurately reflect the law of stress waves propagation in the rock mass, and the transmission coefficient of the stress wave through the fractures with variable stiffness is consistent with the theoretical solution; (3)Employing the viscous absorption boundary model to the discrete particle model, and we achieves the simulation of the far-field stress wave propagation in the finite model; (4)Based on the modeling the dynamic and static stiffness coefficients of the fracture with low JCR are obtained, and the ratio of the dynamic/static stiffness coefficients is about 1.0. This paper can have a significant meaning for the testing and value of the fracture stiffness in the rock mass.