Abstract: Using multiple datasets from meteorological observation, air quality monitoring, lidar detection, and online information of water-soluble ions, a comprehensive analysis was conducted to investigate the characteristics, mechanisms, potential sources, and the comprehensive effects of multiple factors of a high pollution episode of sand storm combined with high PM_2.5 in Jinan from November 25^th to December 4^th, 2018. The results showed that during this period, the main components of pollution were particulate matters. The average concentration of PM₁₀ and PM_2.5 was 294 and 141 μg/m³, respectively, indicating a high level of air pollution. The episode was divided into four stages based on the density ratio of PM_2.5 and PM₁₀. The average concentrations of total water-soluble ions in stages Ⅰ to Ⅳ were (107.3±35.9) (95.2±34.5) (99.0±18.2) and (29.3±9.3)μg/m³, respectively. They accounted for 73.8%, 56.9%, 64.2% and 43.2% of the mass concentration of PM_2.5, respectively. The corresponding sulfur oxidation rate (SOR) was 0.47, 0.42, 0.55 and 0.25, respectively. In contrast, the values of nitrogen oxidation rate (NOR) were 0.42, 0.26, 0.28 and 0.13, respectively. The results also showed that there was an obvious process of secondary conversion in the atmosphere of Jinan, and the conversion degree of SO₂ was stronger than that of NO₂. Meanwhile, the mass-concentration ratio of NO₃^-/SO₄^2- was 2.97, 1.75, 1.69 and 1.45, respectively. This suggested that mobile sources had a more contribution to the pollution than stationary sources. During this episode, the PM_2.5 concentration in Jinan was affected by the local and surrounding cities, as well as the two sand storms. The main potential sources of pollution included Shandong Province, northern Jiangsu Province, northern Anhui Province, central Inner Mongolia Autonomous Region, and the Beijing-Tianjin-Hebei Regions. Unfavorable meteorological factors such as near-ground pressure field, high humidity, and weak winds were important factors that cause to the heavy air pollution. Therefore, the episode was caused by multiple factors including adverse meteorological conditions, primary accumulation and secondary transformation of pollutants, regional transmission, and sand storms.