The invention relates to a multiple-leg-choice movable sofa
machine stretching apparatus. The apparatus comprises a left part, a right part, a switch part, an extension spring, a self-locking spring and a backrest return spring, and the left part and the right part are respectively provided with same leg structures, an S slide spacing connecting piece, an S slide connector 1, a slide connector 2, a slide connector 3, a slide connector 4, a slide connector 5, an S leg drive connecting piece, an S front supporting piece, an S rear supporting piece, an S auxiliary mounting piece, an S mounting side plate, an S seat frame mounting plate, a backrest push piece, an S back spacing piece, a fixed connecting piece, an S back connecting piece, an S back connector, an S stay
rope drive connecting piece, an S stay
rope fixed connecting piece, an S square tube connecting piece and a
flange fixing piece. The quantity of the selectable leg structures is two, and the two leg structures respectively adopt 8 parts and 6 parts, and can respectively cooperate with other parts to form the complete apparatus. The composition, connecting points, spacing and connecting rod drive of the parts are designed, and bearings are used for rotating connection; and the apparatus can comfortably, safely and stably run, and the legs are selectable.