In order to solve the problem of inconformity between rule of laser interfering charge coupled device and traditional “bucket” model, a kind of non-linear model about relationship curve between saturation area and laser power was proposed. It is explained for the non-linear characteristics of saturation pixels on laser interference to charge coupled device(CCD). On one hand, the photocarriers produced by light injection in the detector increase nonlinearly due to the recombination of electron hole pairs. On the other hand, the channel structure of CCD causes some electrons higher than the storage capacity of the potential well to be expelled before diffusion, which reduces the growth rate of the number of saturated pixels, and then causes the nonlinear interference. The interference effect experiment of silicon-based CCD detector irradiated by continuous laser was operated, and the fitting was carried out with the proposed nonlinear model. The results display that mean relative errors between experimental data and fitted data for laser with wavelengths of 473nm, 532nm, 632.8nm, and 1064nm are 7%, 5%, 5%, and 7%, respectively, which proves the effectiveness of the nonlinear model. The researched results will give a hand to perform experiment of laser interfering CCD.