Water conservancy project drainage pipeline capable of preventing backflow

The utility model discloses a water conservancy project drainage pipeline capable of preventing backflow, and relates to the technical field of water conservancy projects, the water conservancy project drainage pipeline comprises a first pipeline, a fixing block is fixedly connected in the first pipeline, a sliding groove is formed in the first pipeline, and the sliding groove is located below the fixing block; a first mounting ring and a second mounting ring are slidably connected into the sliding groove. According to the utility model, through the design of the plugging block, when water in the pipeline flows back, the backflow water can impact the plugging block, and at the moment, the plugging block moves upwards along the sliding groove, and the two sides of the plugging block are attached to the lower part of the fixed block, so that the pipeline can be completely sealed, and the backflow water in the pipeline cannot flow out along the pipe orifice of the first pipeline; and through the design of a rese