A strut is expected as a key technology of stable combustion for SCRAM jet engine. We took up a two-staged combustion strut having an air-intake at the front end, a preburner inside and an injection nozzle at the rear end of the strut. Intake air from the main air stream with high total temperature and high total pressure is effective for preburning hydrogen. The preburned hydrogen is injected into the recirculation zone generated at the rear end of the strut, showing a good flame-holding performance. We could obtain the relationship between the air-intake flow rate, the equivalence ratio and the combustion performance with a unique numerical simulation.