Abstract: Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), a fall armyworm, native to tropical and subtropical areas of America, is an extremely destructive agricultural pest worldwide. To offer the theory reference for risk analysis and comprehensive treatment on S. frugiperda (Smith), the potential geographical distribution and economic loss of S. frugiperda in Qujing, Yunnan Province was studied. Based on the native occurrence data and environmental variables, the potential geographic distribution of S. frugiperda in Qujing was predicted by maximum entropy (MaxEnt) niche model combined with ArcGIS for correlation analysis. The potential economic loss of maize was calculated based on the corn planting area from agricultural bureau and the actual investigation on the feeding and reduction of corn yield caused by the S. frugiperda. The results showed that the direct economic loss caused by the pest to maize was 29.0267 million yuan. Yunnan Province, as the first S. frugiperda invading province, has brought great threat to China’s agriculture. Qujing is located in the eastern part of Yunnan Province, which is the junction of Yunnan, Guangxi and Guizhou provinces. A scientific basis is provided for monitoring, better control and preventing S. frugiperda from further spread into other area.