The weak interlayers are the soft bands with certain thickness in rock, and they are usually of lower strength. According to the physical characteristics and experimental results of rock, a numerical model is first established, and then the model parameters are adjusted and determined. Based on the the simulation method after verification, the rock samples with weak interlayer of different dip angle are simulated by Finite Element Method, and simulations of triaxial tests are completed under different confining stress (5 Mpa, 10 Mpa, 15 Mpa and 20 Mpa). The results show that the dip angle of weak interlayer has a significant influence on the strength and deformation development of rock samples under high confining stress, but the degree of influence varies due to difference of dip angles.