An adjusting structure for a curtain cutting machine, wherein the curtain cutting machine is adapted to cut a curtain which contains a first rail, a second rail, and a plurality of curtain blinds. The curtain cutting machine contains: an elongated base and an adjustment mechanism. The adjustment mechanism contains: a fixing plate including a first orifice and a second orifice; at least one slidable rod being forced to slide in a first sliding travel; a driving unit for driving the at least one slidable rod to slide in a second sliding travel; a first cutting unit corresponding to the second orifice; a second cutting unit driven by the at least one slidable rod to slide; and a third cutting unit including a holder and a third cutter. The holder is coupled with the first orifice, and the third cutter is disposed on the at least one slidable rod.