To identify the most suitable duck breeds for the rice-duck-crayfish integrated system （RDCI）， this study compared the weed management， pest control， and residual crayfish predation abilities of the meat duck group （Wuqin No. 10） and the laying duck group （Nonghu No.2）， using the rice-crayfish continuous culture model （RCCC） as a control. The key findings are as follows： （1） Weed management： the meat duck group’s control efficacy against Alternanthera philoxeroides was 50.40%， repesenting a significant improvement over the laying duck group’s -198.34% （P<0.05）. Additionally， the meat duck group also demonstrated a 56.82% efficacy against Cyperus difformis， surpassing the laying duck group’s efficacy of 37.88%. the meat duck group achieved a 79.31% efficacy against Echinochloa crusgalli， which was slightlt lower than the laying duck group’s efficacy of 81.03%. （2） Pest control： after a 30-day period with ducks present， both the meat duck and Laying duck groups achieved a complete control efficacy of 100% against Chilo suppressalis. The meat duck group demonstrated a control efficacy of 74.93% against Cnaphalocrocis medinalis， which was higher than the Laying duck group’s efficacy of 45.00%. One day after the removal of the ducks， the meat duck group’s control efficacy against Cnaphalocrocis medinalis was 99.20%， surpassing the laying duck group’s efficacy of 94.60%. Both groups achieved a 100% control efficacy against C. suppressalis， with no plant mortality observed. （3） Predation on residual crayfish： the meat duck group exhibited a daily predation rate of 1.67 crayfish tails， which was higher than the laying duck group’s rate of 1.33 tails per day. The meat duck group’s crayfish seed yield in the subsequent year was 60.00 kg/hm²， which was lower than the laying duck group’s yield of 75.5 kg/hm²， but both yields were significantly below the RCCC group’s yield of 670.91 kg/hm² （P<0.05）. Considering weed management， pest control， and the predation abilities of the residual crayfish， it was determined that the Wuqin No. 10 meat duck is better suited for the RDCI.