A typical air pollution process in Beijing, China was analyzed by ground-based lidar network, vehicle-based lidar, meteorological data, PM2.5 mass concentration and backward trajectory results of Beijing and its surrounding areas, from March 9 to march 14, 2018. The results indicated obviously that the air pollution process was a typical regional pollution accumulation and transmission process, and it had a long duration and wide range of influence. During the air pollution process, there is an obvious characteristic of aerosol mass transmission along the southwest transport pathway of Beijing. The polluted air mass transported from the south to Beijing along the southwest pathway, causing the rapidly rise of PM2.5 mass concentration in Beijing. The observation based on lidar network and vehicle-based lidar, can effectively support the researches of pollutants transmission in Beijing-Tianjin-Hebei and its surrounding areas.