The space grid structure is mostly adopted to the sector lock gate of ship lock,and the sector lock gate is the first time to be adopted in the design for 34 m ship lock. To improve the design rationality and safety reliability of gate structure,we combine with the design example of the sector lock gate of the expansion and reconstruction project of Yuxi first ship lock on Heyu line,analyze the key technical difficulties in the design of sector lock gate of the large entrance ship lock from four aspects including the main structure of the gate,the supporting and moving parts,the anti-collision system and the water sealing system,perform finite element simulation analysis of the spatial gate structure for two design water level combinations,design top and bottom pintle structures specifically,and propose solutions in the aspects of surface strengthening technology of moving parts,structural type of anti-collision system and water sealing design. The results show that the stresses of all parts of the gate are within the allowable range,and the moving parts are safe and reliable,the water sealing system has good adaptability. Overall,all of them meet the requirements of use.