The invention discloses a parallel mechanism with two-dimensional translation and two-dimensional rotation. The parallel mechanism comprises a fixed frame, a moving platform and four branched chains which are symmetrically arranged between the fixed frame and the moving platform and provided with a drive device respectively, wherein the four branched chains have two types of structures; the branched chain with one type of structure comprises a straight line guide rail, a drive block arranged in the straight line guide rail and a fixed-length connecting rod of which both ends are provided withrotary hinges; the branched chain with the other type of structure comprises a straight line guide rail, a drive block arranged in the straight line guide rail and a fixed-length connecting rod of which both ends are provided with spherical hinges; the four branched chains with the two types of structures are in crossed arrangement; one end of the fixed-length connecting rod is connected with themoving platform, and the other end of the fixed-length connecting rod is connected with the drive block; and the moving platform is connected with a main platform and a fork-shaped shaft, of which the axial lines are vertical to each other, by a rotary pair, and the main platform can rotate around the axial line of the fork-shaped shaft. The parallel mechanism has the advantages that: the structure is simple; the mode of motion is definite; the requirements on complicated holding-releasing operations are met; and because the connecting rod is the fixed length rod which helps to reduce the inertia load, the parallel mechanism has higher rigidity in different operational ranges, and the high-speed movement is easily realized.