In the actual design of the toner cartridge of the printer, the photosensitive drum and the magnetic drum have a relatively long life and do not need to be replaced when the toner in the toner cartridge is exhausted. Under normal circumstances, the newly replaced toner cartridge can generally print about 2,000 sheets, and the design life of the photosensitive drum can generally reach about 20,000 sheets. Considering that the replacement toner is a substitute brand, the waste toner rate will be relatively higher. It is higher, so under normal circumstances, the entire toner cartridge needs to be replaced when the toner is added about 5 times.