A structure for adjusting a support force of a lumbar pillow, comprising: 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 comprises a lead screw , wherein the lead screw runs through the internally threaded hole , the lead screw is rotatably connected to the backrest bracket , and an extension direction of a rotation axis of the lead screw with respect to the backrest bracket is consistent with a vertical direction of the backrest bracket ; 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, characterized in that the adjustment mechanism further comprises a horizontal rotation shaft ; wherein the horizontal rotation shaft is rotatably connected to the backrest bracket , two ends of the horizontal rotation shaft extend along a widthwise direction of the backrest bracket and are each fixedly connected to a handle , the handle being disposed outside the backrest bracket , and a middle portion of the horizontal rotation shaft is provided with a driving bevel gear ; and one end of the lead screw is provided with a driven bevel gear , wherein the driven bevel gear is meshed with the driving bevel gear , and the lead screw is arranged to be perpendicular to the horizontal rotation shaft . 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 comprises a lead screw , wherein the lead screw runs through the internally threaded hole , the lead screw is rotatably connected to the backrest bracket , and an extension direction of a rotation axis of the lead screw with respect to the backrest bracket is consistent with a vertical direction of the backrest bracket ; 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, characterized in that the adjustment mechanism further comprises a horizontal rotation shaft ; wherein the horizontal rotation shaft is rotatably connected to the backrest bracket , two ends of the horizontal rotation shaft extend along a widthwise direction of the backrest bracket and are each fixedly connected to a handle , the handle being disposed outside the backrest bracket , and a middle portion of the horizontal rotation shaft is provided with a driving bevel gear ; and one end of the lead screw is provided with a driven bevel gear , wherein the driven bevel gear is meshed with the driving bevel gear , and the lead screw is arranged to be perpendicular to the horizontal rotation shaft . <EOS>