Floating supporting cylinder

The utility model discloses a floating supporting cylinder, which belongs to the technical field of supporting cylinders and comprises a shell, and a locking mechanism is mounted in the shell. A supporting mechanism used for supporting a workpiece is installed in the locking mechanism. The locking mechanism comprises a base assembly and a locking assembly. The base assembly and the locking assembly are both arranged in the shell, and the base assembly is arranged on the lower side of the locking assembly. By means of the mode, the top area of the conical piston is increased to the maximum extent, hydraulic pressure needed for achieving the locking pressure effect is reduced, the hydraulic requirement during use is lowered, the mechanism is compact in structure, and the machining and assembling difficulty is lowered; meanwhile, the structure can meet different stroke requirements on the supporting cylinder, an additional screwed joint does not need to be replaced, and the universality of the same screwed joint