An illumination system includes a chip package, a first dichroic film, a second dichroic film, and a third dichroic film. The first dichroic film, the second dichroic film, and the third dichroic film are not parallel to each other and do not cross each other. The chip package includes a first light-emitting chip capable of emitting a first light beam, a second light-emitting chip capable of emitting a second light beam, and a third light-emitting chip capable of emitting a third light beam. The first light-emitting chip, the second light-emitting chip, and the third light-emitting chip are arranged in a row. The first dichroic film reflects the first light beam and transmitting the second light beam, the second dichroic film reflects the second light beam, the first dichroic film and the second dichroic film transmit the third light beam, and the third dichroic film reflects the third light beam.