Abstract: In order to study the long-term variation characteristics of ρ(SO₂) and evaluate the effectiveness of pollution prevention and control policies, the temporal-spatial distribution of ρ(SO₂) in Henan Province from 2001 to 2018 was analyzed through MERRA-2 remote sensing data and according to the implementation of the Action Plan of Air Pollution Prevention and Control. The results show that the spatial distribution of annual ρ(SO₂) in Henan Province was high in the northeast and low in the southwest. The large values appeared in Jiaozuo, Xinxiang and northern Zhengzhou (>50.0 μg/m³), the low values appeared at the borders of Luoyang, Sanmenxia and Nanyang, and the temporal distribution of ρ(SO₂) was higher in winter and lower in spring and summer. The concentration of high value center in winter was 50%-70% higher than that in spring and summer. Before 2011, ρ(SO₂) had an increasing trend in Henan Province, and the concentration increased rapidly in the north. The fastest rate of growth was 3.5-4.0 μg/(m³·a). The ρ(SO₂) decreased in most areas of northwest during the period of 2011-2018, with the fastest deceleration in Jiaozuo-Xinxiang-Anyang area. The ground concentration of SO₂ in northern Henan Province had the digression trend and the rate of decline was greater than 0.4 μg/(m³·a) in Puyang. However, ρ(SO₂) continued to increase slowly in the central and south, with the highest growth rate of 0.6 μg/(m³·a). The results also show that the reduction of the total pollutant emissions and the implementation of the Action Plan of Air Pollution Prevention and Control promoted the reduction of the pollutant concentrations effectively. Compared with the cities located in the Beijing-Tianjin-Hebei transmission channel of air pollution, the ρ(SO₂) in other cities decreased slowly or even increased after 2013. Therefore, the prevention and control of air pollution should be strengthened outside the transmission channel.