The invention relates to a belt-driven swingable parallel connecting rod synchronous telescoping mechanism, which comprises a frame, a first drive pulley, a second drive pulley, a first frame-connecting rod, a second frame-connecting rod, a connecting rod, a first rack, a second rack, a movable platform, a motor and a belt. The first rack and the second rack are always parallel in the process of motion, and can carry out synchronous lifting motion under the drive of the motor, so the movable platform linked with the two racks can carry out planar two-dimensional translational motion. The belt-driven swingable parallel connecting rod synchronous telescoping mechanism has the advantages of simple and compact structure, small occupied floor space, agile action and the like.