The invention discloses auxiliary training device for leg explosive power. The device comprises a base and a cover plate, the cover plate is located on the base, and the base comprises a base body; resistance bearing bracket connecting holes, braking assembly connecting holes, handhold assembly connecting holes, supporting shaft assembly connecting holes and sliding base connecting openings are formed in two sides of the upper surface of the base body, a cover plate assembly installing hole is formed in the side wall of one end of the base body, and the cover plate is arranged on the upper endof the base body. By increasing loading of a running belt, an athlete can achieve strengthening core strength of legs in a short time, the loading capacity can be adjusted, use in different stages and for athletes of different types can be achieved, the flexibility is good, the practicability is better, the device can be applicable to the field of comprehensive fitness, by arranging the braking function, the braking of a force transferring belt is achieved, thereby improving the safety of the device and improving the training efficiency of a user, and it is convenient to promote and use.