Abstract: To find the optimum position of hydraulic radial steel gate drain hole that can meet both strength and drainage requirements, combined with an three support-arm radial steel gate, the ANSYS-based finite element models for the gate that has the same size of drain holes in different positions were established to analyze the impact of drainage hole position on radial steel gate main beam’s strength and local stress. The result show that for the three support-arm radial steel gate, different position of drain holes have different influence on stress distribution of the major beam of the gate. For the middle and low major beams, the drain holes should be arranged at the central of the beam axis; for the upper major beam, the drain holes should be arranged at the position twice hole diameter from the flange.