The invention provides a vacuum adsorbing rotating shaft, comprising a bearing seat, a bearing and a rotating shaft, wherein the bearing seat is provided with a linear circular shaft hole; the shaft hole is provided with bearing mounting grooves; the bearing is mounted in the bearing mounting grooves; the shaft hole between the bearing mounting grooves is in of a smooth surface; the smooth surface is provided with a sealing hole; the upper end of the rotating shaft convexly extends to form an adsorbing head; the top surface of the adsorbing head is of a horizontal structure; the lower end of the rotating shaft rotatably penetrates through the bearing and the sealing hole; the rotating shaft is provided with a smooth part which is in sealed contact with the sealing hole; a vacuum passage penetrating through the top surface of the adsorbing head is arranged along the axis of the rotating shaft from the lower end of the rotating shaft; the vacuum passage is provided with an adsorbing opening at the top surface of the adsorbing head; a vacuum groove communicated with the vacuum passage is arranged at the lower end of the rotating shaft and around the external side of the rotating shaft; and the bearing seat is provided with a main vacuum-pumping passage corresponding to the vacuum groove. The vacuum adsorbing rotating shaft provided by the invention is high in stability and reliability and capable of reducing the friction and reducing the heating quantity.