Abstract: The performance of oxy-hydrogen combustion (deflagration) driver ignited by multiple spark plugs distributed along axis direction were analysed and observed. The causes for low quality of test flow produced by the combustion driver have been found. An improved ignition means with three ignitors at main diaphragm has been developed, by which the incident shock waves with repeatability can be produced and the steadiness of the pressure temperature and velocity of the flow behind the incident shock were improv...