The invention discloses a composite fixture with controllable pressure, and belongs to the field of machine tool fixtures. The composite fixture with the controllable pressure comprises a fixture base, a sliding rail, a large adjusting screw rod, a moving block, a large clamping block, a small adjusting screw rod, a fixing block, a small clamping block, a scale A and a scale B, the lower end of the sliding rail is mounted on the fixture base, the upper end of the sliding rail is clamped in the concave edge of the lower end of the moving block, the large adjusting screw rod is meshed with the moving block, the lower end of the small clamping block is embedded in a dovetail groove of the lower end of a groove formed in the large clamping block, the small adjusting screw rod is meshed with the fixing block, one end of the small adjusting screw rod is fixedly connected with the small clamping block, the scale A is arranged on the large adjusting screw rod, and the scale B is arranged on the small adjusting screw rod. The composite fixture with the controllable pressure solves the problems that the clamping pressure of an existing machine tool fixture is difficult to control and a special fixture is not high in universality, and has the advantages of being simple in structure, reasonable in design and easy to manufacture.