The invention provides a fuse of an electric vehicle. The fuse comprises a promotion module and a trigger module, wherein the promotion module is separated from the trigger module. A first copper barpasses the trigger module and stretches into the promotion module. A through hole is arranged in one end stretching into the promotion module. A second copper bar stretches into the promotion module.The first copper bar is electrically connected with the second copper bar through a main fusion body. The main fusion body seals the lower end of the through hole. A promotion channel and a disconnection channel are arranged in the promotion module and communicate with each other. A promotion device is arranged in the promotion channel. An insulated disconnection grating sheet is arranged in the disconnection channel. The lower end of the disconnection grating sheet downwards stretches into the through hole and contacts with the main fusion body. Explosives are arranged in the promotion device. A trigger for monitoring current passing through the first copper bar is arranged in the trigger module and is connected with the promotion device. When current passing through the first copper barexceeds a set threshold set of the trigger, the promotion device is discharged and ignited by the trigger to push the disconnection grating sheet to thrust the main fusion body so as to allow the first copper bar to be disconnected with the second copper bar. Thus, the fuse is compact in structure and quite safe.