Graded pressure-equalizing combustion solid rocket motor

The invention discloses a graded pressure-equalizing combustion solid rocket motor. The graded pressure-equalizing combustion solid rocket motor comprises front primary combustion chambers and a rearprimary combustion chamber, the front primary combustion chamber and the rear primary combustion chamber are axially connected and communicate with each other, wherein one of the primary combustion chambers is used for filling a fuel rich propellant, and the other one of the primary combustion chambers is used for filling an oxygen rich propellant; the front primary combustion chamber includes a combustion chamber shell, the inner portion of the combustion chamber shell is used for filling the propellant, and after the propellant is filled, a fuel gas flow path is axially formed along the central axis of the combustion chamber shell; the rear primary combustion chamber comprises a hollow outer casing body and an annular spray pipe, wherein a hollow inner casing body is sleeved with the outer casing body coaxially,