The utility model discloses a four-connecting-rod lifting mechanism. The four-connecting-rod lifting mechanism comprises a chassis, a top support and a plurality of connecting rods; one end of each connecting rod is movably connected with the chassis, the other end of each connecting rod is movably connected with the top support, a plurality of connecting rods are arranged in parallel, and synchronization rods are connected between the multiple connecting rods. In this way, two connecting rods can synchronously move through the corresponding synchronization rod so that the lifting stability can be guaranteed. As a quadrangle structure is formed by the chassis, the top support and the two connecting rods, the lifting stability is further strengthened, the lifting mechanism can drop to a lower position, and a wheelchair user can be conveniently transferred to a care bed, a massage bed or a treatment bed. The two connecting rods are hinged to the chassis and the top support, and the stability of the connecting mode is high.