A roller shade cutting machine includes a base, a track assembly, a shade holder, a slat cutting device and a shade cutting device. The track assembly is mounted the base and includes a stationary track and an adjustable track with a ruler slidably mounted on the stationary track. The shade holder is mounted on the stationary track and has a rotating chuck to clamp a roller of the roller shade. The shade cutting device is mounted on the stationary track below the shade holder to cut the spinning roller. The slat cutting device is mounted on the stationary track and has a rolling cutter that is swiftly turned to cut a slat of the roller shade. Therefore, the cutting machine can be used to cut not only the roller but also the slat of the roller shade so that the machine is convenient to use.