Abstract: Analyzing the emission characteristics and change feature of air pollutants from industrial sources during the Winter Olympic Games can provide scientific guidance for the formulation and optimization of air quality assurance schemes during major events. Based on the online monitoring data of 352 industries which have installed CEMS as well as the ambient monitoring data of 150 sites in Weifang City, the paper analyzes the relationship between air quality and emissions during the guarantee period as well as the implementation and emission reduction effect of enterprises in different industries and different control measures. As the results: ① The effection of industry management is well, with the emission reduction of smoke, dust, SO₂ and NO_x of industrial enterprises are 8.8 tons, 92.4 tons and 273 tons respectively, and the ratio of emission reduction is 20%, 31.4%, and26%. The concentrations of PM_2.5, SO₂ and NO₂ are decreased by 24%, 11% and 16% respectively, which means a significant improvement in ambient. ②The emissions of enterprises that production activities have been stopped in the guarantee period are basically reduced completely, and the actual emission reduction (23%-26%) of enterprises that production have been limited are basically consistent with the emission reduction requirements of general control measures (20%-30%), as a result, control measures of enterprises in stop production and limit production are in place. The emission reduction of enterprises with production in limit and freedom is accounting for nearly 90% of the total emission reductions. ③ 12 industries which provided the most percentage of contaminant emission, such as thermal power generation and steel, is contributing 96.7% to the total emission reduction. The emission reduction of gas-related industrial enterprises mainly came from the key emission enterprises. ④ Iron-making enterprises which use production waste heat to undertake residential heating suggest to achieve the corresponding emission reduction effect by controlling the emission of sintering machine.