Abstract  [Aim]  To determine the occurrence patterns and spatial distribution of Spodoptera frugiperda, a significant migratory, agricultural pest, in sorghum fields in Guizhou. [Methods]  Field surveys were conducted in the Anshun, Guiyang, Qianxi, Jinsha, and Renhuai regions of Guizhou Province and 6 aggregation indices, Taylor’s power law, and Iwao’s regression analysis were used to analyze the spatial distribution of S. frugiperda larvae. [Results]  Field surveys revealed that S. frugiperda larvae primarily feed on leaves, causing irregular holes or other damage, during the 6th to 9th sorghum leaf stages. In the 5 surveyed regions, larvae were mainly 3rd instar larvae or younger, with few 5th and 6th instar larvae. The number and density of larvae were significantly higher in southern compared to northern regions. Spatial distribution indices indicate that larvae have an aggregated distribution pattern. There was a highly significant, positive correlation between the infestation rate of sorghum plants and the number of larvae (R = 0.972 9，P < 0.01), which conformed to the regression equation y = 54.646 0x + 5.232 8(R² = 0.946 5). A theoretical sampling model for larval density was developed based on analysis of the spatial distribution pattern: N = (3.84/D²) (1.945 8/x﹣0.664 9). This model defines the number of sorghum plants that should be sampled under different larval densities and allowable error ranges. Based on the larval density control threshold, a sequential sampling interval calculation formula for larvae was derived: T_Iwao(n) = 0.27n ± 1.96. [Conclusion]  During the 6th to 9th leaf stages of sorghum in Guizhou, Spodoptera frugiperda larvae are predominantly in the 1st to 3rd instar stages, exhibiting an aggregated distribution. Infestations are more severe in the southern regions. The study also introduces a sequential sampling model based on pest density, along with control thresholds, providing a scientific basis for field monitoring and integrated pest management strategies.