The extinction coefficient, depolarization ratio, and haze height of atmospheric aerosols during hazy weather are used to realize real-time atmospheric monitoring and study the optical characteristics of aerosols in hazy weather conditions. These characteristics are retrieved based on the observation data obtained from a multi-wavelength aerosol lidar at the Haidian Meteorological Bureau in Beijing, China, from November 4 to 7, 2017. Combining these characteristics with the meteorological parameters obtained from the sounding data, the air mass source and direction during hazy weather conditions are analyzed using the hybrid single particle Lagrangian integrated trajectory (HYSPLIT) model. The analysis concludes that increased relative humidity, low wind speeds, and the presence of an inversion layer are important factors for the formation of hazy weather conditions. The transportation of pollutants through the Hebei Province influences the formation of the haze in Beijing's Haidian District, and haze dissipation is affected by the northwest wind, which provides main conditions for the upward diffusion and disappearance of pollutants.