Based on the characteristics of light transmission in a long path absorption cell, a laboratory simulation system for measuring the extinction characteristics of atomphere pollution particles is designed. The system consists of an extinction characteristics measurement device and an atmosphere pollution particle simulation device. The extinction characteristics measurement device consists of a laser, an open Herriot long path absorption cell, and an optical power meter. In the extinction characteristics measurement device, the laser is divided into two beams. One beam enters the open long path absorption cell, and this beam then is reflected many times by the internal high reflective mirrors of the open long path absorption cell and is emitted from the outlet of the open long path absorption cell. Finally, this beam is received by the optical power meter at the outlet of the open long path absorption cell. The other beam after splitting is directly received by the optical power meter at the entrance of the open long path absorption cell. The extinction coefficient is calculated by the laser powers monitored at the entrance and outlet of the the open long path absorption cell. During the measurement of the laser power, the difference method is adopted to reduce the error caused by fluctuations in laser energy, and improve the accuracy of the extinction coefficient measurement. The open Herriot long path absorption cell can reflect a certain wavelength of light through two fixed high reflective mirrors multiple times to increase the optical path. At the same time, it is convenient to clean the internal mirror and improve the measurement sensitivity of the extinction coefficient. Meanwhile, the concentration of particulate matter for extinction is measured in real-time. The atmosphere pollution particle simulation device is mainly composed of an atmosphere pollution particle simulation generation device and an atmosphere pollution particle collection device. The atmosphere pollution particle simulation generation device is composed of a blower, an atmosphere pollution particulate matter storage box and an atmosphere pollution simulation generation box. The simulation generation of atmosphere pollution particles is to place the air pollution particles in the air pollution particle atmosphere pollution particulate matter storage box, and then the blower is used to blow the particles into the air pollution simulation generation box. In the atmophere pollution simulation generation box, the particles with larger particle size will settle at the bottom of the box due to gravity, and the particles with smaller particle size will enter the pollution simulation detection module with the air flow for extinction measurement. The atmosphere pollution particle collection device is an air filter, which can well adsorb the pollution particles in the pollution simulation detection module, and reduce the pollution to the laboratory. The air pollution particle generation device and the air pollution particle collection device can well control the concentration in the pollution simulation detection module. At the same time, a small meteorological station placed in the pollution simulation and detection module can monitor the concentration of pollutant particles in the module in real time. In order to verify the rationality of the extinction measurement system, the extinction coefficients of particles with different diameters and the extinction coefficients of particles with different components are measured in the laboratory simulation system. By measuring the extinction coefficients of SiO₂ particles with different particle sizes, it is found that the extinction coefficients of SiO₂ particles with different particle sizes are significantly different. And then by measuring SiO₂ particles and AL₂O₃ particles with the same particle size finds that the extinction coefficient of particles with different components are also significantly different, which further explains that particle size and refractive index are the main factors determining the extinction coefficients. By comparing with the extinction coefficient measured by lidar in the atmospheric haze, the reliability and rationality of the extinction simulation measurement system are proved.