The invention relates to a force booster for a fuse cabinet. The force booster for the fuse cabinet includes a shell for fixing in the fuse cabinet; a trip driving member which can perform reciprocating motion is arranged in the shell; the trip driving member has a positive energy storage stroke and a reverse release stroke on the reciprocating stroke of the trip driving member; the force boosterfurther includes an energy storage elastic member connected to the trip driving member for applying an elastic force to the trip driving member to make the trip driving member move toward the releasestroke; the energy storage elastic member is driven by the trip driving member to deform and storage energy when the trip driving member is on the energy storage stroke; the energy storage stroke of the trip driving member is provided with an energy storage completion position; and the force booster further includes a locking and unlocking structure for blocking the trip driving member at the energy storage completion position and unlocking the trip driving member when the fuse is blown. By means of the force booster disclosed by the invention, the driving force of the trip driving member is effectively increased, the separating and tripping effect of the fuse cabinet is ensured, and the safety of the equipment operation is improved.