Lifting semitrailer chassis and lifting semitrailer applying same

The invention discloses a lifting semitrailer chassis and a lifting semitrailer applying the same. The lifting semitrailer chassis comprises a frame, a front auxiliary supporting leg, a rear auxiliary supporting leg and a crane base fixed to the frame. The four corners of the crane base are each provided with a main supporting leg oil cylinder sleeve, after the main supporting leg oil cylinders are connected, the lifting force can be directly transmitted to the ground, the front auxiliary supporting leg and the rear auxiliary supporting leg can bear the lifting moment generated by the lifting distance only with small force, the shearing force and the bending moment borne by a vehicle body in the lifting process are greatly reduced, and vertical deformation is reduced. A fixed platform connecting seat is arranged at the bottom of the crane base, a supporting leg supporting and hoisting mode and a fixed platform supporting and hoisting mode can be achieved, the maximum lifting capacity in the supporting leg sup