An energizing device of a mainspring motor comprises: a positioning platform (40) for positioning and aligning with a mainspring motor and a lifting platform (41) disposed below the positioning platform (40). Positioning rods (42) and an energizing motor (43) are mounted on the lifting platform (41). A rotation shaft of the energizing motor (43) is connected to a protruding head rod (44). The positioning platform (40) is provided with through-holes through which the positioning rods (42) and the protruding head rod (44) can pass. The mainspring motor is provided with positioning holes (30) and a gear rod (25) which, when rotating, enables a mainspring (11) inside a mainspring box (2) to store energy, and the gear rod (25) is provided with a recessed hole on an end face thereof. When the lifting platform (41) moves upward, the positioning rods (42) and the protruding head rod (44) can both pass through the positioning platform (40), the positioning rods (42) are inserted into the positioning holes (30) of the mainspring motor, the protruding head rod (44) is inserted into the recessed hole on the end face of the gear rod (25) of the mainspring motor, and the energizing motor (43) drives the protruding head rod (44) to rotate to energize the mainspring motor. The present invention enables a short energizing time and is safe and reliable.