An asynchronous door knife comprises a track rack and a base plate; a dynamic blade and an unlocking blade which are connected on the front of the base plate in a swinging manner; a knife lifting ball which is arranged on the dynamic blade; a lock hook which is arranged on the back of the base plate and correspondingly buckled with a latch, wherein the unlocking blade is connected on the base plate through a lifting plate; the lifting plate is hinged on the base plate and comprises a first swing arm and a second swing arm; the first swing arm is hinged with the unlocking blade; the second swing arm is connected with an unlocking connecting rod; a lifting hole is additionally formed on the base plate; the middle of the lock hook is hinged with the unlocking connecting rod through the lifting hole.