Bridge plug and bridge plug assembling method

The invention discloses a bridge plug and an assembling method of the bridge plug. The bridge plug comprises a slip bowl, a slip, a cone, an expansion ring and a central pipe. The slip is arranged at one end of the slip seat; the cone is arranged at the other end of the slip; the expansion ring is sleeved on the central pipe and is arranged between the cone and the central pipe; the central pipe is connected into the cone in a screw-thread fit manner; a plurality of slip teeth are embedded in the outer wall of the slip; a first inner conical surface is formed at one end, assembled with the cone, of the slip, and a second inner conical surface is continuously formed at the inner side end of the first inner conical surface; a first outer conical surface is formed at the end, assembled with the slip, of the cone, and a second outer conical surface is continuously formed at the inner side end of the first outer conical surface; the inclination angles of the second inner conical surface and the second outer conica