The invention discloses a seat height adjustment carrying structure. A height adjustment core piece comprises rotating star-shaped bosses and shell fan-shaped cavities corresponding to the rotating star-shaped bosses one to one. The rotating star-shaped bosses are located in the corresponding shell fan-shaped cavities. A plastic handle is an injection-molded piece with an insert. Clamping groove boss sets corresponding to the rotating star-shaped bosses one to one are arranged on the insert. Each clamping groove boss set is composed of two clamping groove bosses. The clamping groove boss sets are inserted into the corresponding shell fan-shaped cavities. Each rotating star-shaped boss is located between the two clamping groove bosses of the corresponding clamping groove boss set. The clamping groove boss sets are driven by the rotating star-shaped bosses to rotate in the shell fan-shaped cavities. On the premise of not influencing the arrangement space of an existing structure, the problem that abnormal sound and scratches are caused when the adjustment angle of the height adjustment core piece is larger than the operation angle of the plastic handle and the plastic handle collides with an outer side large protection plate is solved.