Cement retainer

The utility model discloses a cement retaining device, which belongs to the technical field of underground tools and is characterized in that an upper joint is mounted on one side of a cement retaining device main body, a lower joint is mounted on the other side of the cement retaining device main body, and connecting grooves are formed in openings in one sides of the upper joint and the lower joint; a connecting groove is arranged in the middle of a threaded connecting sleeve in a sleeving mode, clamping blocks are installed on the two sides of the outer walls of a cement retaining device body, an upper connector and a lower connector, buffering anti-corrosion particles cover one side of the middle of the inner wall of the lower connector at equal intervals, a limiting base, a limiting spring and a moving plug can be pushed in the using process, and the moving plug is pushed to move for material guiding; when material guiding is stopped, the limiting spring drives the moving plug to rebound, after rebounding