Abstract: Achieving precise flow measurement and control in the terminal canal networks of irrigation districts remained a persistent engineering challenge. This study examined the hydraulic performance of integrated measurement and control agricultural sluice gate installed at the trapezoidal channel diversion outlet. The overarching goal was to establish theoretical support for the geometric design and field operation of such sluices. By combining experimental measurements with numerical simulations, the research examined the factors influencing the water surface profile upstream and downstream of the regulating sluice, the variation law of Froude number Fr, the diversion ratio R, and the discharge coefficient μ₁ of the agricultural diversion sluice under different gate openings e₁ and e₂. Steady-state flow was modeled using the Volume of Fluid (VOF) method. Four grid resolutions were tested for grid independence verification. The governing equations included the transport equation, continuity equation, Reynolds-averaged equations, turbulent kinetic energy equation, and dissipation rate equation. The equation system was discretized by the finite volume method and solved using a segregated implicit iterative approach.The channel dimensions and boundary conditions matched the experimental setup. Four evaluation metrics were selected to verify the simulation accuracy: maximum absolute relative error (MARE), mean absolute percentage error (MAPE), coefficient of determination (R²), and root mean square error (RMSE). Dimensional analysis based on the principle of dimensional homogeneity was employed to derive the basic overflow formula for agricultural sluices. Grid independence analysis demonstrated that refining the mesh to 1.5 cm or finer produced negligible variation in water depth at the monitoring point. Mesh quality exceeded 0.8 for all four resolutions. These results confirmed accurate grid generation and reliable simulation performance. Validation against experimental data yielded maximum absolute relative errors of 9.96% and 7.08% for discharge and upstream water depth, respectively. The corresponding mean absolute percentage errors were 3.91% and 1.64%. Coefficients of determination reached 0.986 and 0.985. Root mean square errors were 1.14 and 0.45.Water surface fluctuation upstream of the agricultural sluice gate decreased as the gate opening was reduced. The upstream Froude number remained below 0.5 under all hydraulic conditions. Enlarging the regulating sluice gate opening lowered the upstream water level, thereby weakening the backwater effect induced by the agricultural gate. An unstable hydraulic jump formed downstream. Both the height and longitudinal extent of this jump diminished as the regulating gate opening increased. Throughout the tested range, the overall flow regime remained stable and controllable.A positive linear relationship was observed between the relative opening e₁/H and the diversion ratio R under different inflow rates Q₀, which remained valid when varying the side slope coefficient m and sluice width b₁. Increasing the weir height P reduced the flow capacity of the lateral channel, leading to a decrease in the diversion ratio R. Under different channel parameters, the discharge coefficient of the agricultural diversion sluice and the relative opening e₁/H exhibited a power-function relationship, with R² > 0.97 and a mean relative error below 5%. Nonlinear regression was applied to fit discharge prediction formulas for both free-flow and submerged-flow conditions, yielding R² > 0.94. The proportion of predictions falling within ±5% of measured values exceeded 87%, confirming high predictive accuracy. Mean relative errors were consistently below 5%, satisfying the technical standards prescribed for flow measurement facilities in irrigation canals. Field verification of the gate discharge capacity in the terminal canals of the irrigation district confirmed that prediction errors remained within 5%. The agricultural diversion sluice design proposes in this study offers strong applicability, low cost, and ease of promotion, which reduces operational difficulties in practical irrigation. The arrangement of the agricultural sluice aligned with the channel wall can provide insights for the development of intelligent integrated measurement and control sluice equipment, and also provides reference for the design of channel sluice shapes and equipment applications in irrigation areas.