Abstract: In order to investigate the fatigue crack propagation performance of HG785D high-strength steel, study combines experiment and numerical simulation is conducted in this paper. The three point bending specimens of HG785D steel are made and subjected to fatigue crack growth rate tests with a stress ratio of R=0.2. The extended finite element method(XFEM) is used to simulate the crack propagation process. The results indicate that the fatigue life of high-strength steel is 7.61×10⁴ times when the loading load F_max is 7.5 kN; through the experimental and numerical simulation, the crack length and crack tip strength factor curve have the same change trend. Numerical simulation can effectively describe the fatigue crack growth process of SENB3 specimen, and it provides methods and data reference for fatigue life evaluation of high-strength steel.