By volume element dividing of the laser fuse field,a mathematical model for approximate calculation of the fuse cloud-and-fog scattering echo was established based on Mie scattering theory.The scattering echo of uniform cloud-and-fog particles as well as cloud-and-fog particles complying with certain spectral distribution was calculated out with this model.The influence of incident laser wavelength,particle concentration and spectral distribution parameters on the intensity of scattering echo was analyzed.The research results show that:1) For uniform cloud-and-fog particles,the oscillation of fuse scattering echo enhances with the increase of particle size; 2) For the same particle concentration,scattering echo of the cloud-and-fog particle swarm with large radius is significantly higher than that of the cloud-and-fog particle swarm with small radius;and 3) For laser of different wavelength and with a significant difference in the imaginary part of refractive index,the intensity of their scattering echo differs significantly,i.e.,the cloud-and-fog scattering light intensity of laser with a smaller imaginary part is significantly higher than that of laser with a larger imaginary part.The study may provide a theoretical basis for laser fuse anti-cloud-and-fog interference.