Abstract: In order to solve the problem of frequent manual calibration during the continuous monitoring of the emission of particulate matter from fixed pollution sources, which caused by single light scattering method due to instrument drift and easy pollution of optical window, and to realize automatic calibration technology of continuous emission monitoring system on mass concentration of particulate matter combined with light scattering and β-ray attenuation, the effect of filter membrane deformation under negative pressure on the accuracy of monitoring results mass concentration of particulate by β-ray attenuation method was studied, on the basis of the calculation method of thickness influence factor, the correction of the calculation formula of original particle mass concentration was completed. The experiment shows that, compared with the standard weighting method, the average relative error of the revised formula decreases from 8% to 3%, while the correlation coefficient reaches to 0.988, the intercept decreases from 4.935 4 to 1.012 7,which further improves the accuracy of the β-ray attenuation method for monitoring particle concentration in low concentration environment.