Grinding and polishing air floatation main shaft of thinning machine and air floatation method of grinding and polishing air floatation main shaft

The invention discloses a grinding and polishing air floatation main shaft of a thinning machine and an air floatation method. The grinding and polishing air floatation main shaft at least comprises a thrust bearing, a radial bearing and a rotating body arranged in the radial bearing. The thrust bearing comprises an upper thrust bearing and a lower thrust bearing connected below the upper thrust bearing, and the radial bearing is arranged between the upper thrust bearing and the lower thrust bearing; the main shaft is further provided with an air supply port and an exhaust port, the rotating body is provided with an exhaust structure, the thrust bearing and the radial bearing are provided with air supply structures, and middle gaps are formed between the rotating body and the radial bearing, between the rotating body and the upper thrust bearing and between the rotating body and the lower thrust bearing respectively. And the air supply port, the air supply structure, the middle gap, the exhaust structure and