Aiming at the problem that the operation force of the multi-way directional valve of the excavator is too large due to the steady-state flow force in the opening process, the visualization research of multiple physical fields of thermal-fluid- solid was carried out on the throttle groove of the valve core based on ANSYS. By analyzing the flow state under the valve core of the semi- circular throttle groove, the topology structure of the new throttle groove was proposed. A Non-Parametric Regression response surface model was established to study the influence of the new throttle groove structure size on steady-state flow force and mass flow rate. Combined with a multi-objective genetic algorithm, the flow state and steady-state flow force of the valve core before and after optimization were compared and analyzed. The results show that the new groove structure can reduce the steady-state flow force and effectively improve the reversing performance of the multi-way valve during the opening.