The utility model discloses a supporting leg lifting structure, which comprises an internal supporting leg, an external supporting leg and a lifting structure, wherein the internal supporting leg and the external supporting leg are lifted in a sleeving manner; the lifting structure is arranged between the internal supporting leg and the external supporting leg. As an improvement, the lifting structure comprises a lifting slider, a sliding groove and an elastic body, wherein the sliding groove is matched with the lifting slider; tooth slots are arranged at both sides of the sliding groove; the lifting slider is correspondingly provided with engaging teeth meshed with the tooth slots or demeshed with the tooth slots; the tooth slots and the engaging teeth between the lifting slider and the sliding groove are extruded by the elastic body to be engaged; the appropriate part of the external supporting leg is provided with a positioning hole matched with the lifting slider; according to the supporting leg lifting structure, the lifting slider which can be meshed with and demeshed with the tooth slots of the sliding groove is provided, and the lifting slider is matched with the positioning hole of the external supporting leg, the engaging teeth on the lifting slider and the tooth slots on the sliding groove are extruded by the elastic body to position the internal supporting leg and the external supporting leg in a matching manner; and through pressing the lifting slider in the positioning hole, the engaging teeth and the tooth slots are demeshed, so as to realize lifting. The supporting leg lifting structure is simple in structure, convenient to operate and reliable in performance.