The invention discloses a flexible hinge-guided plane X Y theta three-degree-of-freedom precision compensator. The flexible hinge-guided plane X Y theta three-degree-of-freedom precision compensator comprises a compensation device and a mounting base; the compensation device includes three sets of fixed blocks, a terminal actuator, three displacement driving devices, and three sets of three flexible branched chains respectively connected between each fixed block and the terminal actuator; the fixed blocks are fixed on the mounting base; the three fixed blocks are arranged around the terminal actuator in an annular array form; two ends of the flexible branched chains are hinged to the terminal actuator and the fixed blocks through hinges; the displacement driving devices are restrained on the fixed blocks; and the end parts of the displacement driving devices are fixed at a tail section of a first lever through screws. A transmission device formed by the three sets of flexible branched chains achieves an amplifying effect, and can output and amplify fine displacements of the displacement driving devices as bigger displacements to drive the terminal actuator to obtain a larger operation adjusting space, so that the displacements generated by the driving devices can be quickly transferred to the terminal actuator through the flexible branched chains.