Disclosed is a mop with a collapsible mop disk, comprising a mop rod (1) and a mop disk (2) connected to a lower end of the mop rod (1). The mop disk (2) comprises a main disk (3) and an attached disk (4) located at one side of the main disk (3). The lower end of the mop rod (1) is connected to the main disk (3). The main disk (3) is connected to the attached disk (4) via a flexible piece (5). When the floor at an interface with a wall is swept, the attached disk (4) can be folded upward so as to form a plane fitted with the wall on the mop disk; therefore, the floor at an interface with the wall can be effectively swept.
