The invention provides an active-seal type aerostatic bearing. The bearing comprises a stator, a rotor and an air seal device, wherein the stator comprises a cylindrical cavity; an air inlet is formed in the stator; the rotor is a rotating shaft which is rotatably arranged in the cavity of the stator in a penetration manner and carried by the stator; the air seal device is used for actively retarding the escape of gas in the bearing. Compared with the prior art, the bearing provided by the invention is simple in structure and has the advantages that the escape of the gas in the bearing can be actively retarded to ensure that active sealing is formed and the changing gradient of gas pressure in the bearing is reduced, which is conductive to increasing the running stability of the bearing.