Open cut column-free arched subway station unearthing structure and construction method

The invention provides an open-cut non-column arched subway station unearthed structure which comprises a station body structure, a vertical supporting structure, an enclosure structure and a soil retaining structure, the station body structure comprises a top plate, a middle plate, a bottom plate and two side walls oppositely arranged in the transverse direction, and an upper-layer underground space is defined by the top plate, the side walls and the middle plate; a lower-layer underground space is defined by the middle plate, the side walls and the bottom plate; the vertical supporting structure is supported between the top plate and the bottom plate, two top plate soil outlets oppositely formed in the two sides of the vertical supporting structure are formed in the top plate, and two middle plate soil outlets oppositely formed in the two sides of the vertical supporting structure are formed in the middle plate; the soil retaining structure is fixed to the top plate and encloses the soil outlet of the top p