Circulating screwing-on and screwing-off device at top of tubular column

The utility model discloses a pipe column top circulation screwing-on and screwing-off device which is arranged at the upper end of a mast in a sliding mode and comprises a simple faucet and a hydraulic power tong. The upper end of the simple water faucet is connected with a water hose, and the hydraulic power tongs are arranged below the simple water faucet and used for screwing on and screwing off the lower end of the simple water faucet and a pipe column; one end of the hydraulic power clamp is rotationally connected with an installation support, and the end, away from the hydraulic power clamp, of the installation support is in sliding connection with the upper end of the mast and can slide up and down along the mast so as to drive the hydraulic power clamp and the simple faucet to move up and down together. The simple faucet and the top end of the pipe column can be screwed on and screwed off, a drilling fluid circulation channel at the top of the pipe column is built, the structure is simple, and stabil