A type of Mg/CO2 powder rocket engine configuration and a combustion organization plan with three times intake of oxidant gas were put forward based on the research of powder rocket engines at home and broad as well as the design methods of powder burners in industry. Experimental researches on its working process were carried out. The engine combustion efficiency and chamber deposit were studied under different oxygen gas inlet plans under the oxygen to fuel ratio 4∶1

so as to provide the basis for setting the parameters of Mg/CO2 powder rocket engine multiple-start working conditions. The engine hot-experiment results showed that the flame failed to keep stable and the engine can not work normally when the oxygen to fuel ratio in combustion chamber head was too large. The highest combustion efficiency was 64.0% among all hot experiments. There were almost no deposits in combustion chamber under the oxygen gas intake plan when the amount ratio of fluidization gas

cyclone gas and lateral gas was 2∶0.5∶1.5.