A plane parallel type three-freedom-degree precise positioning work table has three flexible branched chains which are total the same in structure and respectively and correspondingly arranged on the inner sides of three equal sides of a base of a triangular structure and a movable platform arranged on the inner sides of the three flexible branch chains and arranged at the center of the base, wherein the base, the three flexible branched chains and the movable platform are integrally formed, the three flexible branched chains are in flexible connection with the base, displacement input ends of the three flexible branched chains respectively correspond to three included angles of the base, the movable platform is in flexible connection with the three flexible branched chains, a groove is formed between the inner side of each included angle of the base and the corresponding flexible branched chain, a piezoelectric ceramic driver is horizontally arranged in the groove, one end of the piezoelectric ceramic driver is in hertz contact with the displacement input ends of the flexible branched chains, and the other end of the piezoelectric ceramic driver is fixedly connected on the base through bolts. The plane parallel type three-freedom-degree precise positioning work table is compact in structure, flexible to control, high in static and dynamic stiffness, high in kinematic accuracy, low in inertia, free of error accumulation, free of friction and heating and fast in responding.