[Aim]  In order to effectively control the fall armyworm, Spodoptera frugiperda, in the subtropical border area of China, reduce the population base of the fall armyworm in the source area and slow down its spread in China. [Methods]    The field control efficacies of six commonly used insecticides in Dehong Prefecture (25% spinetoram, 25 g/L deltamethrin, 240 g/L methoxyfenozide, 200 g/L chlorantraniliprole, 10% tetrachlorantraniliprole, 10% cyantraniliprole) against fall armyworm was comparatively evaluated through the change of survival rate of fall armyworm larvae, damage degree of maize, damage rates of maize plants and field efficacy period of insecticides. Correlation analysis and curve regression analysis were used to study the relationship between rainfall and larval survival. [Results]  25% Spinetoram, 200 g/L chlorantraniliprole, 10% cyantraniliprole, 240 g/L methoxyfenozide, and 10% tetrachlorantraniliprole had good control effects on fall armyworm, and their average field duration was 15.7, 13.0, 11.6, 9.0 and 9.0 d, respectively. In combination with the three indexes of survival rate of fall armyworm larvae, reduction rate of maize damage degree and infested maize plants, the integrated control effect of 25% spinetoram, 200 g/L chlorantraniliprole, 10% cyantraniliprole, 10% tetrachlorantraniliprole and 240 g/L methoxyfenozide was significantly higher than that of 25 g/L deltamethrin 13 days after treatment (F=7.055, P=0.003), and reached 79.62%, 58.49%, 10.39%, 52.11% and 30.39%, respectively. However, the first 3 insecticides were only used once, and the last 2 insecticides were used twice. Therefore, field persistence and control effectiveness of different insecticides was different. From May to September 2019, the rainfall in Dehong Prefecture first increased and then decreased, while the population of fall armyworm gradually decreased. The correlation analysis showed that there was a significant correlation between larval survival and rainfall, which belonged to a moderate negative correlation. The value of probability and correlation coefficient was 0.044 and﹣0.511, respectively. According to the curve regression analysis, there was a significant curve relationship between the number of surviving fall armyworm larvae and rainfall, with the discriminant coefficient (R²) being 0.471 8, curve model P=0.028, and equation y=-105.90ln(x)+513.94. [Conclusion]  The first recommended insecticides for controlling fall armyworm in Dehong prefecture were 25% spinetoram and 200 g/L chlorantraniliprole, followed by 10% cyantraniliprole, 240 g/L methoxyfenozide and 10% tetrachlorantraniliprole. Combined with rainfall, the alternating use of the above recommended insecticides twice during summer maize growth period can effectively control the fall armyworm.