Liquid controlled variable-diameter stabilizer

The invention relates to the field of drilling equipment, in particular to a liquid controlled variable-diameter stabilizer. The liquid controlled variable-diameter stabilizer comprises a hollow outercylinder, three spiral fins are arranged on the outer cylinder, a plurality of piston holes are successively formed in each spiral fin in the axis direction of the outer cylinder, pistons are arranged in the piston holes, and the pistons are connected with the piston holes in a sealed mode through piston sealing; and an upper mandrel assembly, a cone assembly, a transposition mechanism, a lower mandrel assembly and a position indicating mechanism are arranged successively in the outer cylinder in the axial direction of the outer cylinder. According to the liquid controlled variable-diameter stabilizer, the structure is simple, and thefree, flat and extending states can be smoothly realized according to the predetermined requirements; and the liquid controlled variable-diameter stabilizeris connected to the upper