A fuse includes an outer cartridge body, an inner cartridge body provided inside the outer cartridge body, a fuse core provided inside the inner cartridge body, two inner copper bushes provided at and covering two open ends of the outer cartridge body, and two outer copper bushes provided at and covering the two inner copper bushes and two open ends of the outer cartridge body. One end of one inner copper bush is a first open end, and the other end is a first closed end. An end face of the first closed end has a first opening. The first open end of the inner copper bush and the outer cartridge body form an interference fit. An end of the fuse core extends and passes through the first opening, and is fixed to the end face of the first closed end.