The invention relates to the technical field of municipal administration and discloses a road dotted line marking device capable of automatically cleaning a to-be-marked road surface. A carriage is included, and moving wheels and a spraying type mark scriber are arranged at the bottom of the carriage. A first motor and a cylinder body are arranged in the carriage, an output end of the first motoris fixedly connected with a first gear, the upper end of the first gear is fixedly connected with a rotating rod, the end, away from the first gear, of the rotating rod is movably connected with a piston rod, and the end, away from the rotating rod, of the piston rod is hinged to a piston. According to the road dotted line marking device capable of automatically cleaning the to-be-marked road surface, a sweeper is driven by a rocker arm and a second motor to swing back and forth on the road surface while rotating; and the piston is matched to reciprocate left and right in the cylinder body sothat a coating is repeatedly sucked into or output from the cylinder body, the spraying type mark scriber intermittently sprays the coating by controlling the amount of the coating, namely intermittent drawing and scribing are achieved, and therefore the effects of automatically sweeping a to-be-marked road surface and automatically drawing dotted lines are achieved.