The invention relates to a method for realizing controlled doping of nano silicon quantum dots, which belongs to the technical field of nano photoelectronic devices. The method comprises the steps of preparing a doped amorphous silicon film, preparing a doped amorphous silicon multilayer film, preparing doped nano silicon quantum dots in virtue of laser radiation, and the like. The invention provides a preparation method for convenient, rapid and effective controlled doping of the nano silicon quantum dots, and the method has short processing time, does not damage a film and a substrate in a nanosecond level, and is compatible with the current micro-electronics processing technology. In the implementation process, the method mainly adopts a high-energy laser to irradiate the surface of the film to obtain the nano silicon quantum dots with uniform size, simultaneously realize the controlled doping of impurity concentration and improve the photoelectric property of the film. The doped nano silicon quantum dots prepared by the method have wide application prospect in the fields of future nanoelectronics, nano photoelectronic devices and the like.