【Aim】 This study explores the sex differences in the structure and function of gut microbiota in Pomacea canaliculata, aiming to provide a scientific basis for analyzing the sex differences in the environmental adaptability of P. canaliculata during the invasion process. 【Method】 High-throughput sequencing was employed to analyze the gut samples of male and female snails from different geographical locations (Hainan, Guangdong, and Fujian). The diversity indices of gut microbiota were comprehensively analyzed. Non-metric multidimensional scaling (NMDS), permutational multivariate analysis of variance (PERMANOVA), and Tax4Fun functional prediction were conducted to analyze the composition, abundance differences, structural similarities, and functional differences of gut microbiota in male and female snails. 【Result】 The Chao1 index of gut microbiota showed sex differences (P<0.05), which were not observed in other alpha diversity indices (P>0.05). Sex differences (P<0.05) existed in the abundance of some phyla (Firmicutes, Bacteroidota, Spirochaetota, and Cyanobacteria) and a genus (Lactococcus) of the gut microbiota. The geographical location significantly affected the β diversity of gut microbiota in P. canaliculata, while sex had no significant effect on it. In addition, there was no significant difference in the abundance of KEGG pathways in the gut microbiota of male and female snails from Hainan. Male snails had higher abundance of membrane transport pathways than female snails from Guangdong (P<0.05). Among the samples from Fujian, male snails had higher abundance of cellular processes and signaling pathways (P=0.01), and female snails had higher abundance of translation pathways (P<0.05). 【Conclusion】 Sex mainly changes the abundance rather than diversity of gut microbiota, while geographical location significantly shapes the community structure and function of gut microbiota in P. canaliculata.