Abstract: Using the finite element numerical simulation method, the paper aims to simulate rail surface crack and the surface wave scatter in the crack and wave conversion, and to use the surface wave spectrum method for quantitative analysis of crack. Artificially machined cracks on the test block and a 60 kg/m of rail respectively were used to verify the simulation results. Surface breaking cracks have a low-pass effect for the surface wave, and high frequency surface wave cutoff frequency is inverse proportional to the depth of the crack.