A damping adjustment device (300, 400, 500) for a window covering system, wherein the window covering system comprises a covering material and a driving device to be driven by the covering material while the covering material expanding or collecting; the damping adjustment device (300, 400, 500) comprises: a damping module (310, 410, 510a, 510b) comprises a first damping unit (312, 412, 512a, 512b) and a second damping unit (314, 414, 514a, 514b), and a damping force can be outputted by the damping module (310, 410, 510a, 510b) to the window covering system when the first damping unit and the second damping unit (314, 414, 514a, 514b) generate an interaction force in between by a relative motion between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b); and an adjusting module (330, 430, 530) connected to the damping module (310, 410, 510a, 510b) for operating with the damping module (310, 410, 510a, 510b) simultaneously, wherein the damping force from the damping module (310, 410, 510a, 510b) is adjusted by the adjusting module (330, 430, 530) altering a relative position of the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b) when the relative motion occurs between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b); the damping adjustment device (300, 400, 500) is characterized in that: the damping module (310, 410, 510a, 510b) is configured to be driven by the driving device to output the damping force to the driving device when the covering material expanding, wherein the adjusting module (330, 430, 530) increases the interaction force between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b) for increasing the damping force from the damping module (310, 410, 510a, 510b) as the driving device operating. a damping module (310, 410, 510a, 510b) comprises a first damping unit (312, 412, 512a, 512b) and a second damping unit (314, 414, 514a, 514b), and a damping force can be outputted by the damping module (310, 410, 510a, 510b) to the window covering system when the first damping unit and the second damping unit (314, 414, 514a, 514b) generate an interaction force in between by a relative motion between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b); and an adjusting module (330, 430, 530) connected to the damping module (310, 410, 510a, 510b) for operating with the damping module (310, 410, 510a, 510b) simultaneously, wherein the damping force from the damping module (310, 410, 510a, 510b) is adjusted by the adjusting module (330, 430, 530) altering a relative position of the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b) when the relative motion occurs between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b); the damping adjustment device (300, 400, 500) is characterized in that: the damping module (310, 410, 510a, 510b) is configured to be driven by the driving device to output the damping force to the driving device when the covering material expanding, wherein the adjusting module (330, 430, 530) increases the interaction force between the first damping unit (312, 412, 512a, 512b) and the second damping unit (314, 414, 514a, 514b) for increasing the damping force from the damping module (310, 410, 510a, 510b) as the driving device operating.