This sensor performs the concentration of particle detection based on the MIE scattering principle. When the outside air passes evenly through the optical acquisition room, the particles in the sampling gas scatter through the light beam. The photoelectric acquisition unit converts the scattered light signal into voltage pulse signal, which is pre-amplified and converted from AD into digital signal. The measured number of voltage pulses is the number of particles, and the amplitude of the voltage pulse reflects the size of the particle optical equivalent particle size. The mass concentration is determined by calibrating the particle scattering intensity to determine the particle mass concentration in the test environment.