Method for constructing subway station by enlarging and digging shield tunnel by adopting mining method

The invention discloses a method for constructing a subway station by enlarging and digging a shield tunnel by adopting a mining method. The method comprises the following steps of: (1) firstly advancing a platform layer tunnel passing through a station by adopting a shield machine; (2) excavating a vertical well to elevation of the platform layer tunnel of the station at one end of the station; (3) constructing along with a tunnel vault and manufacturing a pipe shed, perforating by adopting a large pipe shed advance support and grouting; (4) constructing along with the tunnel vault and manufacturing a sleeve valve pipe, and grouting for complementing and reinforcing; (5) enlarging and digging in the platform layer tunnel by adopting the mining method; (6) dismounting and recovering pipe pieces; and (7) constructing and manufacturing a concrete structure comprising a secondary lining, a platform plate and a rail head wind channel. In the invention, the shield machine participates in construction of the subway station, a cave is firstly excavated, then an underground station is enlarged, excavated and constructed by adopting the mining method, respective advantages of the shield machine and the mining method are fully played, and waste of equipment and underground space resource caused by a special large-diameter shield machine is avoided.