Abstract: Two sets of helium safety valves are installed in the safety discharge system in the primary loop of 10MW High Temperature Helium Cooled Test Reactor (HTR-10, which are nuclear safety class 1 components and one of the key devices to guarantee the safety of HTR-10. The present paper gives the design requirements and structural features as well as performance requirements of the helium safety valves. The demonstration test for performance of the helium safety valves were carried out in special test system according to the requirement of ASME Section III code. The test result showed that the performance of the helium safety valves can meet the design requirement and relevant nuclear codes.