Lifting appliance for lifting ring groove in cylindrical workpiece and lifting method

The invention discloses a lifting appliance for a lifting ring groove in a cylindrical workpiece and a lifting method. A lifting appliance for lifting a ring groove in a cylindrical workpiece comprises a mandrel, a lifting part is arranged on the mandrel, a circular truncated cone part is arranged at the lower end of the mandrel, at least two limiting grooves are formed in the circular truncated cone part, and a supporting plate capable of being clamped in the limiting groove is arranged on each limiting groove; a lantern ring is arranged on the outer side of the mandrel, an inverted-L-shaped guide groove is formed in the lantern ring, and the supporting plate can be movably connected with the lantern ring in a rotating mode along the guide groove. According to the lifting appliance for the lifting ring groove in the cylindrical workpiece and the lifting method, the requirement for lifting nuclear power key equipment made of stainless steel is met, the lifting appliance is particularly suitable for heat treat