In order to simulate the dynamic light scattering signal of superfine particles, an auto-regressive (AR) model of the random process is made by analysing the character of dynamic light scattering signal. The module parameter is identified by Levison-Durbin algorithm and the method of selecting module order is given when scattering signal of unimodal and bimodal distribution particles is simulated. Thus a simulative method of dynamic light scattering signal based on AR module is put forward. By this method, the scattered signal of 50 nm, 300 nm, 1000 nm and scattered signal of 50 nm and 1000 nm, 100 nm and 500 nm, 300 nm and 1000 nm were respectively simulated when the module order was 1, 1, 1, 57, 28, 40. Their simulative autocorrelation function of light intensity accords with their theoretical autocorrelation function. The unimodal distribution’s relative error of inverting particles size by cumulants and the bimodal distribution’s relative error of inverting particles size by double exponential were respectively less than 0.58%, 3.7%. The results show that the signal simulation of unimodal distribution particles need one order module, and the signal simulation of bimodal distribution particles with differernt sizes need differernt order module.