The invention discloses a 
solid fuel regression rate test device. According to the invention, a 
combustion chamber with a rectangular recess structure is adopted. An igniter is arranged on the front of an upper cap, and communicates with the 
combustion chamber. A 
pressure measurement port is fixed on the middle of the upper cap, and communicates with the 
combustion chamber. An air inlet 
pipe is connected to a balancing chamber. An air inlet plate is positioned between the balancing chamber and the 
combustion chamber. A Laval 
sprayer nozzle is fixed on the back part of the 
combustion chamber. A fixing slot is positioned at a central part on the bottom in the 
combustion chamber. An agent column is placed in the fixing slot, and testing can be carried out. During the operation of the test device, combustion 
chamber pressure intensity and oxidant flow are both adjustable. Through the changes on the pressure intensity and the flow, a 
functional relationship between a burning rate and the pressure intensity and the oxidant flow can be obtained, such that 
test complexity can be effectively reduced. The test device provided by the invention has the advantages of simple structure, low cost, easy 
processing, and safe and reliable operation. With the test device, the 
solid fuel regression rate of a 
hybrid rocket motor can be tested. The test device has low requirements on various propellants. Once a 
propellant is prepared into a rectangular body, testing can be carried out by using the test device provided by the invention.