A dot projector with automatic power control includes a housing covering a substrate with an installing space and a platform therein, an automatic power control integrated circuit, a photodiode and a reflector disposed under the platform of the housing, a collimator disposed in the installing space of the housing and a diffractive optical element bonded on the platform of the housing. Whereby a laser diode emits a laser light to the reflector for the laser light to be reflected perpendicularly through the collimator to the diffractive optical element; then the diffractive optical element produces a plurality of light spots and the a stray light is also produced from the laser light. The photodiode of the automatic power control integrated circuit then detects the stray light and produces a feedback signal transmitted back to the laser diode for adjustment of the laser emission power in order to control the light spots produced by the diffractive optical element.