The present application provides a three-dimensional (3D) image system, comprising a structural light module, configured to emit a structural light, wherein the structural light module comprises a first light-emitting unit, the first light-emitting unit receives a first pulse signal and emits a first light according to the first pulse signal, a duty cycle of the first pulse signal is less than a specific value, an emission power the first light-emitting unit is greater than a specific power, and the first light has a first wavelength; and a light-sensing pixel array, configured to receive a reflected light corresponding to the structural light.