Water retaining dam capable of automatically cleaning floating objects

The invention relates to a water retaining dam capable of automatically cleaning floating objects. The water retaining dam comprises a robot used for automatically cleaning garbage on the water surface, and further comprises a dam body and a collecting tank; the left side of the dam body is an upstream face, the right side of the dam body is a downstream face, a mud retaining wall is arranged at the left side of the dam body, a flow guide wall is arranged at the right side of the dam body, and water passing holes are formed in the lower portion of the dam body at intervals; flashboard holes communicated with water passing holes in the top face of the dam body are formed in the upper portion of the dam body, flashboards are arranged in the flashboard holes, and the water level height is controlled according to the number of weights in the flashboards; and a first impeller is pushed by water flowing in the water passing holes to drive a second impeller to rotate, water is injected into acleaning cover when the