Disclosed is a photo-stimulation method and device. The method includes the following steps: providing a light-emitting diode (LED) illuminant which is a yellow, red, or blue LED and illuminating a subject by the LED illuminant to promote collagen synthesis, to suppress microbial growth, or to inhibit melanin synthesis, wherein the yellow LED is in an illuminance range from 1,000 to 3,500 lux, the red LED is in an illuminance range from 6,000 to 9,500 lux, and the blue LED is in an illuminance range from 3,000 to 7,000 lux.
