The invention discloses a lifting device of a lifting system. The lifting device comprises an installing frame, a plurality of lifting mechanisms and a plurality of guiding mechanisms; the installingframe is provided with a strip-shaped groove matched with racks on pile legs; the lifting mechanisms are symmetrically arranged on the two sides of the strip-shaped groove, and the guiding mechanismsare arranged on the two sides of the strip-shaped groove; each guiding mechanism comprises a guiding plate, a base, a locking wedge block assembly and a stop block; the guiding plates are arranged inbase installing grooves; the locking wedge block assemblies are arranged below the bases; each locking wedge block assembly comprises a first wedge-shaped block, a second wedge-shaped block and a distance adjusting rod; and the stop blocks are further arranged below the first wedge-shaped blocks and the second wedge-shaped blocks. According to the lifting device of the lifting system, by adjustingthe locking wedge block assemblies, telescopic movement is made to be generated between the first wedge-shaped blocks and the second wedge-shaped blocks so that the guiding plates can be pushed to move. The lifting device of the lifting system has the beneficial effects that the replacing frequency of the guiding plates is reduced, and cost is reduced.