Provided is an electric booster of a locomotive. The electric booster of the locomotive comprises a jacking system and a traveling system. When the electric booster of the locomotive is in a no-load state, a front traveling wheel (3) and a rear traveling wheel (7) fall to the ground, a front friction wheel (2) and a rear friction wheel (6) are suspended, and a push rod (8) is pushed to enable the electric booster to move and turn a corner; when the electric booster of the locomotive works, a jack (17) enables a movable support (15) to upwards move through a manual pump (12), the supportable portion of the locomotive is jacked to be at a certain height, part of the weight of the locomotive is borne by the electric booster, a spring (9) is compressed at the moment, the front friction wheel (2), the rear friction wheel (6), the front traveling wheel (3) and the rear traveling wheel (7) fall to the ground at the same time, and the electric booster and the locomotive are driven by a motor (4) to move forwards at the same time. According to the electric booster of the locomotive, due to the facts that the electric booster bears part of the weight of the locomotive to generate friction, and the motor drives the electric booster and the locomotive to move together, the structure is reasonable and compact, driving force is larger, the movable support (15) is replaced to adapt to different supporting heights, operation is convenient, and is not limited by places, and place changing and movement of the locomotive are facilitated.