Flexible positioning tool capable of rotating in four positions

The utility model discloses a flexible positioning tool capable of rotating in four positions, which comprises a positioning support structure used for clamping a casting and mounted on a rotating shaft of a machining center, the positioning support structure comprises a bottom plate, and a plurality of fixed footstocks are mounted on the bottom plate so as to respectively mount a support block, a second oil pressure support cylinder and an oil pressure corner cylinder. A transverse positioning rod capable of abutting against the casting is arranged on one side of the supporting block, the top of the supporting block and the top of the second oil pressure supporting cylinder can both support the bottom of the casting, and the oil pressure corner cylinder lowers the bottom of the casting through a pressing plate. A jacking oil cylinder and an upper fixing plate are fixed on the top plate, the jacking oil cylinder is connected with a floating connector, the floating connector is arranged at the top of a lower d