The invention discloses a robot plane work point rapid positioning system and a rapid positioning method thereof, and belongs to the technical field of robots. The positioning system comprises a worktable, a camera, a robot body, a control device and an upper computer; the camera is mounted on the top face of the worktable through a support, the camera is located above the workpiece placing part,a lens of the camera faces the workpiece placing part, a base is fixedly arranged on the top face of the worktable, the lower end of a first joint arm is horizontally and rotatably mounted on the upper end face of the base, the lower end of a second joint arm is vertically and rotatably mounted on the upper end of the first joint arm, the head end of the fourth joint arm is mounted on a rotating shaft on the tail end of the third joint arm, and the head end of the fifth joint arm is rotatably mounted on the tail end of the fourth joint arm. Manual teaching is not needed, the system is suitablefor the working conditions that the process requirement is simple, the workpiece structure is simple, the work track is simple, and the work point distribution is simple, positioning is accurate andefficiency is high.