Abstract: Ground test is the important and indispensable method for the research and development of hypersonic vehicle,and the acquisition of the high-enthalpy test flow with long enough test time in the test is one of the key challenges for the shock tunnel.Based on detonation-driven shock tunnel,several factors that are of significant influences on the test time are discussed and the corresponding solutions for extending test time are proposed in this paper,including the tailored condition,the shock starting process in the nozzle and the interaction of reflected shock and boundary layer,aiming to meet the requirement for the test time of supersonic combustion experiments.Through the application of the proposed methods,a large detonation-driven shock tunnel has been successfully developed,which can provide the test time of more than 100 microseconds and are capable of duplicating the hypersonic flight conditions.