To pinpoint the most suitable duck breeds for the Rice-duck-crayfish integrated system, this study contrasted the weed management, pest control, and residual crayfish predation abilities of the meat duck group (Wu Qin No.10) and the Laying duck group (Nong Hu No.2), with the Rice-crayfish continuous culture system serving as the control. Here are the key findings: 1. Weed management: The meat duck group achieved a significant weed control efficacy of 65.83%, which was substantially higher than the Laying duck group's 11.09% (P<0.05). Specifically, the meat duck group's control efficacy against Alternanthera philoxeroides was 50.40%, a notable improvement over the Laying duck group's -198.34% (P<0.05). The meat duck group also demonstrated a 56.82% efficacy against Cyperus difformis, outperforming the Laying duck group's 37.88%, and a 79.31% efficacy against Echinochloa crusgalli, which was marginally less than the Laying duck group's 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 had an 74.93% control efficacy against Cnaphalocrocis medinalis, which was higher than the Laying duck group's 45.00%. A day after duck removal, the meat duck group's control efficacy against Cnaphalocrocis medinalis was 99.20%, surpassing the Laying duck group's 94.60%. Both groups achieved 100% control efficacy against Chilo suppressalis, with no plant mortality observed. 3. Predation on residual crayfish: The meat duck group had 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 the weed management, pest control, and residual crayfish predation abilities, it was determined that the Wu Qin No.10 meat duck is better suited for the RDCI.