Due to the advantages of good monochromatic, high brightness and strong directivity, laser is widely used in ranging and target recognition. However,the laser have a weakness,that is easy to be affected by the natural environment,especially the weather of the fog,which has become a bottleneck restricting the development of laser detection technology.In order to solve the problem that laser detection is affected by fog scattering during laser transmission in the atmosphere, a new method of anti-fog scattering laser detection is proposed by adding the wave-front measurement technology. Firstly, the interaction mechanism of laser and fog is introduced, Secondly, the phase fluctuation difference between the hard target and the fog echo is analyzed. Due to the scattering effect, the echo phase of fog will be seriously distorted. According to the working principle of shack Hartmann detector, the wavefront phase of incident wavefront can be recovered. Finally, a laser fuze test device for wavefront measurement is constructed to test the backscattering phase of hard target and fog. The experimental results show that the phase fluctuation of hard target is slow, and the phase fluctuation of fog is more severe. By comparing the wavefront parameters of hard target and fog, the hard target and fog can be effectively distinguished, which provides a new idea for target recognition and anti- jamming of laser detection.