The invention relates to the technical field of toy guns, and provides a toy gun shot accelerating device. The toy gun shot accelerating device comprises a fixed base and at least one pair of accelerating flywheels; the accelerating flywheels are transversely distributed on the fixed base; when multiple pairs of the accelerating flywheels are provided, all the pairs of the accelerating flywheels are correspondingly arranged in a shot driving direction in sequence; motors are arranged under the accelerating flywheels, and are arranged in the fixed base; output shafts of the motors are fixedly connected with the corresponding accelerating flywheels; the diameters of the accelerating flywheels are smaller than and equal to the outer diameters of the motors; two accelerating flywheels in eachpair of the accelerating flywheels are opposite in rotating direction; shot channels for enabling shots to pass through are formed between the pairs of the accelerating flywheels; the shots are flexible shots; and the shots can be extruded by the pairs of the accelerating flywheels, and can pass through the shot channels. The toy gun shot accelerating device adopts small-diameter accelerating flywheels, can improve the rotating balance performance, reduces the shot blockage probability, greatly reduces the section size, and is convenient for internal component layout and appearance design.