A curtain cutting machine contains: a base, a first cutting mechanism, and a movable platform. The base includes a fixed platform having a front segment and a rear segment. The first cutting mechanism includes a lower cutting assembly with plural first orifices and has an upper cutting assembly with at least one second orifice. The movable platform includes two support racks, two slidable adjusting devices, and a holding plate. The two support racks are arranged on a rear side of the fixed platform of the base and extend upwardly, each of the two slidable adjusting devices is mounted on each of the two support racks and moves forward and backward on each of the two support racks, the holding plate is connected with each slidable adjusting device to hold a curtain, and the holding plate moves forward and backward on the two support racks with the two slidable adjusting devices.