Normal-pressure tool changing device and normal-pressure cutterhead

The utility model discloses a normal-pressure tool changer and a normal-pressure cutterhead, and solves the problem that time and labor are wasted when a sealing seat is wholly replaced after the sealing seat is accidentally abraded in the prior art. The normal-pressure tool changing device comprises a welding seat fixed on a front panel of a tool disc, a tool cylinder assembly is detachably arranged in the welding seat, a sealing seat assembly is arranged at the outer end of the welding seat, a detachable lining is arranged between the tool cylinder assembly and the sealing seat assembly, and the sealing seat assembly is connected with the tool cylinder assembly. Sealing structures are arranged between the lining and the cutter cylinder assembly and between the lining and the sealing seat assembly. Preferably, the sealing structure is a sealing ring and/or a guide ring. The inner surface of the lining replaces the inner surface of the sealing seat to be matched with the cutter cylinder for sealing, meanwhile