A supporting rack having a compensating mechanism includes a rack body, an action force compensating assembly, a transmission element and a supporting plate. The rack body has a base and support arms. The action force compensating assembly is provided in the rack body. The elastic element is firmly connected to the base. One end of the dragging piece is connected to the hooking plate. The rotating piece is provided on a distal end of the support arm. The other end of the dragging piece is connected to the rotating piece. One end of the transmission element is firmly connected to the rotating piece and pivoted on the support arm. Via the above arrangement, an appropriate force can be applied to the supporting plate. When the user intends to adjust the supporting plate, the elastic element can generate an effect for compensating the action force, thereby providing a better operation feeling.