To explore potential strategies for red swamp crayfish （Procambarus clarkii） in controlling weeds in rice fields， it was hypothesized that P. clarkii could directly consume weed seeds. Quantitative feeding experiments were conducted using feed as the control group （Cg） to assess the feeding capacity of P. clarkii on seeds of five common rice field weeds （Ludwigia prostrata， Lp； Leptochloa chinensis， Lc； Echinochloa crusgalli， Ec； Eclipta prostrata， Ep and Ammannia baccifera， Ab）， along with its antioxidant performance and gut microbiota response. Results indicated significant differences in daily consumption and consumption rates of different weed seeds fed by P. clarkii （P<0.05）. The mean daily consumption of Lc， Ab， Lp， Ec and Ep seeds was 0.033， 0.027， 0.059， 0.047 and 0.031 g/ind.， respectively. P. clarkii showed significantly higher consumption of Lp seeds compared to Lc， Ab， and Ep （P<0.05）， and higher consumption of Ec seeds compared to Ab seeds （P<0.05）. However， consumption of weed seeds by P. clarkii was significantly lower than that of the control group （0.1 g/ind.）. The GSH-Px enzyme activity in the hepatopancreas of P. clarkii did not show significant differences among treatment groups （P>0.05）. The MDA content in Ec group was significantly higher than in the other treatment groups （P<0.05）， measuring 7.41 nmol/mgprot； there were no significant differences among the other treatment groups （P>0.05）. The SOD enzyme activity in the Ab group was significantly higher compared to the Lc， Ep， and Cg groups （P<0.05）. The CAT enzyme activity was significantly higher in the Ab group compared to the Ep group （P<0.05）. In the Lp group， the SOD enzyme activity was significantly higher compared to the Lc and Cg groups （P<0.05）. There were no significant differences in α-diversity indices of gut microbiota among different treatment groups. The dominant phyla in the gut microbiota of P. clarkii were Proteobacteria， Tenericutes， Actinobacteria， and Firmicutes， collectively comprising over 99% relative abundance across all treatment groups. Specifically， the relative abundance of Actinobacteria was significantly higher in the Lp and Ec groups， at 9.72% and 5.74%， respectively， compared to other groups. Dominant genera included Acinetobacter， Citrobacter， Aeromonas， Rhodobacter， Shewanella， Clavibacter， Pseudomonas， Lactobacillus， and Arthrobacter. In conclusion， P. clarkii can directly consume seeds of common weeds in rice fields， showing a preference for seeds of Lp and Ec seeds. However， excessive consumption of Ec seeds can lead to oxidative damage in the organism， while seeds of Ab and Lc are consumed in smaller quantities. The gut microbiota of Procambarus clarkii exhibits strong environmental adaptability and can process a variety of complex plant materials. These findings provide valuable insights into understanding the changes in weed biodiversity in rice-crayfish co-culture systems.