The strain softening model and the null model in FLAC3D code are adopted respectively to describe the mechanical behavior of the rock and crack, and the superfine element division method is adopted to divide the calculation model to simulate the crack propagation. This numerical calculation model is adopted to study the effect of crack length, kink crack length, dip angle, kink crack inclination, interval and number on the crack propagation path and rock mass mechanical behavior under uniaxial compression. The calculation results are as follows. The uniaxial compressive peak strength has effects with the crack length and bending length. The peak strength of the sample increases when the dip angle changes from 30° to 90°. When the two parts of the crack are perpendicular to each other, the peak strength of the sample has the highest peak intensity. With the increase in the crack interval, the interaction among the cracks gradually decreases and the peak strength of the samples gradually increases. The crack number has much effect on the sample’s failure mode, and the peak strength of the samples gradually decreases with the increase in crack number. Finally, the model test is used to verify the rationality of the simulation results.