Aiming at the problem that the grating stripe phase measurement method needs over three phase-shift grating stripe images to extract the phase by the phase-shift method

which makes the entire reconstruction process complicated

a method for extracting the phase using single grating stripe image is proposed for three-dimensional reconstruction of the rail surface. Firstly

the Hilbert transform is used to achieve phase shift of single grating stripe image. Secondly

the phase-shift formula is used to get the variation of wrapped phase

and continuous phase distribution is obtained by unwrapping phase. Then

the continuous phase is put into the phase-height mapping relationship to obtain the height distribution of the rail surface and reconstruct three-dimensional model for rail surface. Finally

the traditional Stoilov five-step phase-shift method is used to reconstruct the rail surface. By analyzing the simulation results and according to the actual conditions

the proposed method can well achieve three-dimensional reconstruction of rail surface

and its errors are less and running speed is faster than the Stoilov five-step phase-shift method. It is more suitable for online detection.