Abstract: Frequency Modulated Continuous Wave (FMCW) laser fuze has better resistance to interference than the pulse laser fuze, but it is still affected by cloud and fog. In order to study the influence of FMCW laser fuze parameters on the cloud and fog echo, the cloud and fog echo of FMCW laser fuze in the case of different transmitting-receiving distances, laser wavelengths and relative positions was simulated by using FMCW laser fuze detection model. The simulation results show that transmitting-receiving distance and laser wavelength of FMCW laser fuze have obvious effect on the cloud and fog echo, the greater of transmitting-receiving distance and the shorter of laser wavelength in the visible light and near-infrared band, the weaker of cloud and fog echo. The simulation results of this paper can be used to optimize the design of FMCW laser fuze for the improvement of anti-interference ability.