The invention discloses a well periphery reinforcement cage. The well periphery reinforcement cage comprises annular stress main ribs, hoops and U-shaped embedded steel bars. The U-shaped embedded steel bars are opened downwards and welded to the annular stress main ribs. The U-shaped embedded steel bars are evenly arranged along the well periphery, and the number of the U-shaped embedded steel bars is the same as the number of well seat holes in the periphery of a well seat, and the top face width of the U-shaped embedded steel bars is matched with the width of the well seat holes. In the above structure, a body steel bar supporting structure is formed by the annular stress main ribs and the hoops and is used for bearing the outside tension and shearing force, and deformation and cracks are prevented. The U-shaped embedded steel bars are matched with the well seat holes in the periphery of the well seat in number, position and top face width. During installing, the U-shaped embedded steel bars are used for penetrating the well seat holes to fix the well seat, and therefore the well seat is conveniently installed and prevented from moving. By the adoption of the provided well periphery reinforcement cage structure, the problem of well periphery sinking or frequent local damage can be effectively solved, the maintaining frequency is reduced, and the service life is prolonged.