The invention discloses a rail-self-adaptive motion trolley adjusting device and a using method thereof. The device comprises a motion rail, a movable trolley and a control device, wherein the motion rail comprises a bottom plate, an inner rail, an outer rail and a rack, wherein the bottom plate is fixed on the ground by ground bolts; the inner rail is arranged on the inner side of the bottom plate; the outer rail is arranged on the outer side of the bottom plate; the rack is positioned on the bottom plate and fixed in the middle of the bottom plate; the movable trolley comprises a movable flat panel, a follower plate and a driving device; the driving device comprises a driving gear, a driving gear driving shaft, a driven gear, a driven gear driving shaft, a first guiding wheel, a first guiding wheel guiding shaft, a first rolling wheel, a second rolling wheel, a third rolling wheel, a second guiding wheel, a second guiding wheel guiding shaft, a third guiding wheel and a third guiding wheel guiding shaft; the control device comprises a motor and a speed reducer; rotation motion of the motor can be changed into linear or circular motion along the rack. The device has a simple and novel structure, and the design is easy for machining, the cost is relatively low, and the reliability is high.