The present invention discloses a method for designing a backrest movement mechanism and a backrest movement mechanism designed using same. The method is implemented by analyzing the movement trail of a point A which bears the largest body pressure on a human spine. The backrest movement mechanism comprises an upper frame (1) and a backrest frame (2), and further comprises a backrest connecting mechanism (3), wherein a movement track is provided on the backrest connecting mechanism (3), and the backrest frame (2) is movably connected to the upper frame (1) via the backrest connecting mechanism (3) and moves along the movement track relative to the upper frame (1). The backrest movement mechanism changes the motion between the backrest and a seat cushion from a revolute pair to a sliding pair such that a mechanical rotating point between the backrest and the seat cushion is as close as possible to a rotating point of the human body, so that when the backrest angle is adjusted, the back of the human body can be comfortably in contact with the backrest, and accordingly the relative displacement caused by the relative motion between the back of the user and the backrest can be minimized, so as to minimize the "back rubbing sensation", thereby giving the user the most comfortable experience.