Abstract: A knife that can be quickly assembled and disassembled comprises a blade and a handle that are removably connected to each other through a connection assembly, and further comprises a knife clip, a knife disc and a handle ring. The left end of the blade is provided with a knife rod. A step is provided at the connection between a main body of the blade and the knife rod. A knife clip is sleeved outside of the step. The handle ring and the knife disc are provided parallel on the left and right sides respectively, and are respectively sleeved outside of the knife rod. The handle comprises a handle sleeve and a built-in sleeve that is fixed at the right end of the inner hole of the handle sleeve.