The application and implementation of total light scattering were studied to monitor particulate matter mass concentration in large areas. By means of structural design and modern technology, it removed the influence of environment background light in the process of photoelectric conversion, in order to avoid the disturbance on the system′s stability because of light source intensity′s fluctuation, the light intensity feedback was applied to compensate for it. Using the multiple wavelength method, combined with the Lambert-Beer law and Mie scattering theory, it implemented particle concentration detection in wide open spaces. Compared the system′s calculated results with the standard instrument, the Pearson correlation coefficient is 0.988 9, it indicates that the data has good consistency, the range can reach 0-400 mg/m3, the response time is 1 min. It provides a rapid and real-time method to monitor particulate matter mass concentration in large areas.