The invention relates to a pull-up exerciser. The pull-up exerciser comprises a base and a stand column. The top end of the stand column is connected with a top cantilever in a pivoted mode, the tail end of the cantilever is connected with a linkage cable in a linked mode, the other end of the linkage cable drives a clamping-pulling rotating piece to rotate, the clamping-pulling rotating piece is constantly pulled by an elastic part, and a pull ring unit is arranged at the other end of the cantilever to pull a supporting plate to move vertically in cooperation with a pull rope and a plurality of pulleys. The bottom end of the stand column is connected with a rotating rod assembly in a pivoted mode, the other end of the rotating rod assembly is connected with the supporting plate in a pivoted mode, and an auxiliary pushing unit is arranged between the rotating rod assembly and the base and used for providing upward pushing force for the supporting plate. A linkage hook rod is arranged at the first axis point of the rotating rod assembly and connected with the rotating rod assembly coaxially, and the linkage hook rod cooperates with a corresponding hook column of the clamping-pulling rotating piece to constantly lock the low-point static position of the rotating rod assembly and the supporting plate. Only when the supporting plate bears gravity, the cantilever is pulled downwards, and the linkage rod hook is unlocked from the clamping-pulling rotating piece, can the supporting plate be pulled by the pull ring unit; when the external force of the pull ring unit disappears, the supporting plate descends under continuous gravity and restores to be locked to the low-point static position.