A linear driving system comprises a fastening rack, a power source, a screw nut, a screw limiter, and a screw. The power source is disposed on the fastening rack. The screw nut is disposed on the fastening rack and connected to the power source so that the screw nut may be driven by the power source for in situ rotation. The screw limiter comprises a limiting slide rail disposed on the fastening rack and a limiting slide block disposed on the limiting slide rail in a movable manner. The screw is screwed with the screw nut and connected to the limiting slide block of the screw limiter so that the screw may be moved back and forth along the axial direction of the screw nut by the in situ rotation of the screw nut under the limitation of the screw limiter. By employing the screw nut to drive the screw, the present invention may reduce the space of the linear driving system occupied inside the prosthesis.一種線性驅動系統,包含有一固定架、一動力源、一螺帽、一螺桿限制器,以及一螺桿,動力源設於固定架,螺帽設於固定架且連接動力源,使得螺帽能被動力源所驅動而原地旋轉,螺桿限制器具有一設於固定架之限制滑軌與一可位移地設於限制滑軌之限制滑塊,螺桿螺接於螺帽且連接螺桿限制器之限制滑塊,使得螺桿能夠在螺桿限制器的限制之下藉由螺帽之原地旋轉而沿著螺帽之軸向往復位移,如此運用螺帽來驅動螺桿的情況下,可以達到減少線性驅動系統佔用義肢內部之容納空間的效果。10‧‧‧線性驅動系統20‧‧‧固定架21‧‧‧第一端座22‧‧‧第二端座23‧‧‧連接座30‧‧‧動力源31‧‧‧馬達32‧‧‧第一皮帶輪33‧‧‧第二皮帶輪34‧‧‧傳動皮帶40‧‧‧螺帽50‧‧‧螺桿限制器51‧‧‧限制滑軌52‧‧‧限制滑塊60‧‧‧螺桿
