Staged pressurized combustion solid-propellant rocket engine

The invention discloses a staged pressurized combustion solid-propellant rocket engine. The staged pressurized combustion solid-propellant rocket engine comprises a front primary combustion chamber, arear primary combustion chamber, a pressurization chamber and a main combustion chamber which are successively connected with each other along an axial direction, wherein the rear end of the main combustion chamber is connected with an injection pipe; an outer pressurization channel and an inner pressurization are arranged in the pressurization chamber; the inner pressurization channel is axiallyconnected with the front primary combustion chamber and the main combustion chamber so as to pressurize the gas flow passing through the inside of the inner pressurization channel; the inner pressurization channel is axially connected with the rear primary combustion chamber through the front primary combustion chamber; the outer pressurization channel is axially connected with the rear primary combustion chamber and the