The invention relates to the technical field of water conservancy projects, and discloses a water conservancy project silt treatment device which comprises a box body, the left side of the box body communicates with a discharging pipe, the front portion of the box body communicates with a collecting box, a separating device is arranged on the inner wall of the box body, and a settling device is arranged on the inner wall of the box body; and the settling device is located below the separating device, the rear portion of the box body communicates with a pipeline, the top wall of the box body communicates with a feeding pipe, the inner wall of the box body is fixedly connected with a filter screen and a filter plate, and the filter plate is located at the rear portion of the filter screen. According to the invention, river water about to enter the pipeline can be directly filtered through the filter screen, mud and gravel existing in the river water can be filtered, then the river water can be directly discharged from the pipeline, silt cannot enter the pipeline, the mud can be prevented from adhering to the inner wall of the pipeline, meanwhile, the gravel is adsorbed to be accumulated, and smoothness of the pipeline can be guaranteed.