Preloading type hydrostatic guide rail

The invention discloses a preloading type hydrostatic guide rail. The preloading type hydrostatic guide rail comprises a base, a slide carriage, an air source assembly and an oil supply mechanism. The slide carriage is arranged on the base in a sliding mode, a static pressure cavity is formed in the side face, close to the limiting sliding groove, of the limiting protruding block, the slide carriage is further provided with an air inlet, an air outlet, an air pressure cavity and at least one air pressure block, the air pressure block is fixedly arranged in the air pressure cavity and comprises a first smooth face and a second smooth face, and the first smooth face is located above the second smooth face. The length of the first smooth face in the airflow flowing direction in the air pressure cavity is smaller than that of the second smooth face in the airflow flowing direction in the air pressure cavity, the air inlet communicates with the air pressure cavity and is close to the first end of the air pressure