The disclosure describes a touch device including a touching area having a first edge and a second edge; two reflective lens arrays and two laser source modules which are all disposed at the first edge and the second edge respectively, wherein each laser source module includes a laser diode and a diffractive optical element assembled in front of the laser diode for separating a laser beam projected from the laser diode to a plurality of laser beams with equal magnitude, the laser beams are distributed in a parallel arrangement over the touching area by the reflective lens array; and two receiving devices disposed at the corresponding edges of the first edge and the second edge respectively. The receiving device includes a plurality of sensing units, wherein each sensing unit receives one of the laser beams respectively.