The utility model discloses a lamination-type seal device of a steam turbine high-pressure gas injection insertion pipe, and relates to a seal device, aiming to solve the problems that the seal structure of the existing steam turbine high-pressure gas injection insertion pipe has poor seal property, great gas leakage and low gas injection efficiency. The lamination-type seal device provided by the utility model comprises a compression ring, a plurality of outer seal rings and a plurality of inner seal rings, wherein the outer seal rings and the inner seal rings are arranged at intervals, and are sleeved on the outer side of the gas injection insertion pipe; a radial clearance is reserved between the inner seal rings and an inner cylinder steam injection annular groove; and a radial clearance is reserved between the outer seal rings and the steam injection insertion pipe. The lamination-type seal device of the steam turbine high-pressure gas injection insertion pipe provided by the utility model has a good seal effect and less gas leakage, and is used for the seal of the steam turbine high-pressure gas injection insertion pipe.