The serious attenuation of laser signals caused by fog will take some influences on the laser fuse detection. Therefore, this paper focuses on the attenuation characteristics of a green laser in the fog. On the basis of Mie scattering theory, an attenuation model of laser radiation by the fog at 0.532 μm is established, and the attenuation characteristics of the laser at different visibilities are contrasted and analyzed by simulation and calculation. Then, the veracity of attenuation model is validated by a simulated fog experiment. Theory analysis and experimental results indicate that the laser beam is dependent on the visibilities in the fog, and it increases with decreasing visibilities. The laser at 0.532 μm has a stronger transmittance in the fog and it can be above 60% at a visibility of 50 m. Furthermore, the light transmission values measured in the experiment are basically consistent with calculated ones and the maximum error between them is about 4%, which proves the correctness of the attenuation model of laser radiation at 0.532 μm. The study provides theoretical basis for the green laser application in a detection system worked in the fog.