The structure for adjusting a support force of a lumbar pillow includes: a backrest bracket, a lumbar pillow, an elastic support, and an adjustment mechanism; wherein a top of the lumbar pillow is flexibly connected to a front side of the backrest bracket; one end of the elastic support is connected to a back of the lumbar pillow, and the other end of the elastic support is provided with a slider, the slider being provided with an internally threaded hole; the adjustment mechanism includes a lead screw; and in response to the lead screw rotating with respect to the backrest bracket, the slider slides upward and downward along the vertical direction of the backrest bracket to change a support angle of the elastic support for the lumbar pillow, such that a magnitude of the support force of the elastic support to the lumbar pillow is adjusted.