In order to study the light field statistical property when the laser is scattered by rotated diffuser, combining the statistical model of multi-pixel photon counter (MPPC), the Fano factor which describes the photons fluctuation is gained through adopting the second-order momentum and average value of the photon statistics. Then, the curve fitting of the Fano factor produces the number of thermal modes μ and the parameter B which is the combination of the gain coefficient γ and the cross-talk probability ε for the photo-detector. The experimental results are as follows. The number of thermal modes for the echo signal increases from 289 to 1229 when the driving voltage increases from 20 to 1280 mV, and the increasing speed decreases with the increase of driving voltage for the diffuser. The parameter B can reflect the variance of cross-talk probability between the neighbouring pixels due to the coefficient γ which is a constant during the course of measurement. The results suggest that the cross-talk probability decreases when the rotating velocity increases (the increase of the driving voltage). The curve fitting of the Fano factor only gives the qualitative description of the cross-talk, while there is no information of the gain coefficient in the fitting. The quantitative analysis of gain coefficient and cross-talk probability can be achieved through the research of the third-order momentum for the arriving photons.