The invention discloses a hoop connecting steel ring sealing piece. The hoop connecting steel ring sealing piece comprises a pipe base, a control valve, a sealing steel ring, a sealing pad, a flange and a fluid input pipe, and is characterized in that the pipe base is provided with the control valve; the control valve communicates with the pipe wall of the fluid input pipe; the sealing pad is arranged on one side of the sealing steel ring; the section of the sealing pad is trapezoidal; the sealing pad is made of rubber; a flange connecting quick joint is for being connected with a water inletpipe; and the flange and a blind plate are arranged at the other end of the fluid input pipe to form a sealed shape. The hoop connecting steel ring sealing piece is simple in structure and excellent in generality, can be refitted based on most common pumps, and is simple and reasonable in structure, excellent in crystallization preventing effect and reliable and safe in sealing performance.