The invention discloses a novel motor-driven mechanical stretching device. The improved novel motor-driven mechanical stretching device comprises a left side component and a right side component whichare symmetrical, the left side component comprises a leg stretching mechanism, a seat plate linkage mechanism and a backrest mechanism, the seat plate linkage mechanism comprises a front mounting piece, one end of the front mounting piece is pivoted to the front portion of a bottom connecting rod, the other end of the front mounting piece is pivoted with a first front rotating piece, the middle of the front mounting piece is pivoted with a second front rotating piece, the other end of the second front rotating piece is pivoted with a side connecting rod piece, the front end of the side connecting rod piece is pivoted with the middle of the first front rotating piece, the rear end of the side connecting rod piece is pivoted with a rear rotating piece which is pivoted with a rear mounting piece, the other end of the rear mounting piece is pivoted to the rear end of the bottom connecting rod, and the rear rotating piece and the front rotating piece I are pivoted with an assembling side plate simultaneously. The problems that an existing seat plate linkage mechanism is complex in structure, large in number of parts, high in manufacturing cost and high in clamping stagnation risk are solved.