As a common equipment in sandblasting equipment, the inhaled sandblasting gun is an important component for particle transportation and acceleration. In order to study the internal flow field and particle motion of the inhaled sandblasting gun and the influence of the incident angle of the pellet inlet and the diameter of the mixing chamber on the suction and acceleration of the inhaled sandblasting gun,the CFD software Fluent was used to simulate the gas-solid coupling. The results show that the smaller the incident angle of the pellet inlet is, the better the transport and acceleration performance of the pellet are; with the change of the diameter of the mixing chamber, there is an optimum value of the blasting gun’s ejector coefficient, which has the best conveying effect of the granule, and the optimal value also decreases with the increase of the inlet pressure; the smaller the diameter of the mixing chamber is, the better the acceleration effect of the particles is. It provides reference for the design and selection of inhaled sandblasting gun.