Cylinder shrinking device capable of circulating in and out and oil cylinder barrel repairing process

The invention discloses a cylinder shrinking device capable of circulating in and out and an oil cylinder barrel repairing technology, and relates to the technical field of oil cylinder barrel repairing. The cylinder shrinking device comprises a clamping part used for fixing one end of a cylinder barrel and driving the cylinder barrel to rotate around the axis and a moving part capable of reciprocating in the axial direction of the cylinder barrel; a heating end capable of extending into the cylinder barrel and a cooling end located outside the cylinder barrel are fixed to the moving part, in the radial direction of the cylinder barrel, the heating end is right opposite to the cooling end in position, and when the moving part reciprocates, the heating end circularly heats the inner wall of the cylinder barrel in the axial direction of the cylinder barrel, and the cooling end circularly refrigerates the outer wall of the cylinder barrel; the heating end circularly heats the interior of the cylinder barrel from