Mass concrete winter construction thermal insulation structure and construction method thereof

A mass concrete winter construction heat preservation structure relates to the technical field of mass concrete construction and comprises a concrete pouring bin face, a key groove formwork used for pouring concrete is fixedly arranged on the concrete pouring bin face, and a plurality of profile steel stand columns are vertically arranged on the concrete pouring bin face. A plurality of profile steel stand columns are evenly distributed on the inner side of the key groove formwork in the circumferential direction of the key groove formwork, the profile steel stand columns are provided with air-costal membrane supporting beams, the air-costal membrane supporting beams are provided with an air-costal membrane roof, and the air-costal membrane roof is fixedly connected with the air-costal membrane supporting beams. The key groove formwork is further provided with a sealing assembly which is used for blocking a gap between the air costal membrane roof and the key groove formwork so that the air costal membrane ro