Novel middle-column-supported additionally-arranged elevator capable of directly reaching original gate of resident

The invention provides a novel middle-column-supported additionally-arranged elevator capable of directly reaching an original gate of a resident. The additionally-arranged elevator is arranged on theouter side of an old building; and according to the additionally-arranged elevator, a stair middle main supporting column from the ground to the highest layer is built in the turning position of an original stair handrail and the position beside the turning, the supporting column is used for supporting a stair-free walkway on one side and a stair cross beam and stairs on the other side, the stair-free walkway is arranged between a gate platform and an elevator gate platform, and stair sections of the stairs on the other side are rebuilt to be connected with the elevator gate platform. The additionally-arranged elevator has the effects that the resident does not need to walk up and down one step of the stairs any more when taking the elevator, and the problem that the old people walk up and down the stairs is thor