The invention relates to a spring operating mechanism. The spring operating mechanism comprises a spring cylinder, and a spring and a spring tray installed in the spring cylinder. The spring cylinderis internally provided with a screw rod extending out of the spring tray, a pre-tightening nut for jacking the spring tray to pre-tighten the spring is connected to the screw rod, a locking nut for preventing the pre-tightening nut from loosening is also connected to the screw rod, a separation sleeve between the locking nut and the pre-tightening nut is arranged on the screw rod, the thickness ofthe sleeve wall of the separation sleeve is defined as a, the thickness of the position, at the thickest position of the hole wall of the threaded hole of the locking nut, is defined as b, the thickness of the position, at the thickest position of the hole wall of the threaded hole of the pre-tightening nut, is defined as c, and a is smaller than any one of b and c. Through arrangement of the separation sleeve, the pre-tightening nut is prevented from rotating with the locking nut being screwed to facilitate screw of the locking nut so as to conveniently regulate the pre-compression amount ofthe spring, and the problems are solved that the pre-compression amount of the spring is difficult to adjust due to the fact that the pre-tightening nut rotates with the locking nut when the lockingnut is screwed in the prior art.