Laser particle sensor can obtain the number and quality of suspended particles in the air per unit volume, which is called particulate matter concentration. Meanwhile, it can output as a digital interface.Based on the principle of laser scattering, when the air outside uniformly passes through the specially designed air duct, the laser light is scattered on the suspended particles in the air, and the information processing circuit converts the light intensity signal of the scattered light into a voltage pulse signal through the photoelectric sensor. After preamplification, AD converts into a digital signal, and then the microprocessor MCU based on the MIE theory algorithm (by noise processing and optimal algorithm) to obtain the number of particles of equivalent particle size per unit volume, resulting in particulate matter the equivalent particle size and the number of particles of different particle sizes per unit volume, the output is the mass and number of particles of each concentration in a unit volume.Our product adopts the laser sensor detection of particle concentration technology, based on the principle of laser scattering, and currently, only a few companies have posed this technology around the world. Although it is getting more mature, we have to say that the display of the readings still has inadequacies inconsistency, repetitiveness, and stability. In fact, this just has a slight effect on the usage scenario.