The utility model belongs to the technical field of the axis body processing equipment and specifically relates to an upper end is vertical to be provided with one downwards and to promote the cylinder that full -automatic clamping device that axis body quenches is provided with a support column on the base, be provided with the connecting plate in the upper end of crane, corresponds the positionwith the support column and be provided with the through -hole on the connecting plate, is provided with a thimble in the through -hole, is fixed with the barrel of vertical direction in the top of connecting plate, at the barrel the upper end of thimble be provided with inward cavity, be provided with the end cover at the port of cavity, the telescopic link of promotion cylinder pass inside the connecting hole gets into the cavity, and the telescopic link tip in the cavity is provided with and promotes the piece, the utility model relates to a full -automatic clamping device that axis body quenches, is through promoting special connection the between cylinder and the thimble, realizes promoting the cylinder and drives the thimble and promote to can break away from with the thimble duringdecline, realize that the gravity of the centre gripping make full use of thimble of axis body is realized.