Process for early connection of near subway deep foundation pit main body structure and early disassembly of mid-partition wall

The invention discloses a near subway deep foundation pit main body structure early connection and mid-partition wall early removal process. The process comprises the steps that underground structure construction is conducted layer by layer in a foundation pit from bottom to top; when construction of a foundation slab of the foundation pit is completed and the design strength is achieved, the middle partition wall of the underground structure of the bottommost layer is dismantled, a plurality of columns are reserved in the middle partition wall at the dismantled part at certain intervals, the middle partition wall below a construction trestle area is not dismantled, holing is conducted only at the position of a structural beam, and a support replacement belt is constructed; the beam plates of the middle partition wall cut-off areas of every two adjacent foundation pits are connected in a penetrating mode, structural beam penetrating is conducted on the middle partition wall areas which are not dismantled unde