The basic structure and principle of spatial filter based on linear array CCD were introduced, and the algorithm of basic spatial filter was simulated and validated by MATLAB. A differential algorithm was proposed to solve the problem of strong fundamental frequency interference in the spectrum of basic spatial filter, and computer simulation and real belt pulley motion video verification were carried out. The influence of the parameters of the filter on the measurement results was analyzed and simulated. The selection range of parameters such as grating period width, period number, CCD pixel value, ADC sampling resolution and sampling time length was determined. Spacial filter based on linear array CCD structure has the characteristics of low cost, simple installation and debugging, low noise and so on.