Abstract: A single photons communication method and system is provided. In an example, an information loading module in a transmitting terminal of the single photons communication system may code to-be-sent target information as a corresponding target modulation frequency according to a pre-saved relationship between information and modulation frequency, and perform frequency modulation on a quantum state of communication light generated by a light source by using the target modulation frequency so that the transmitting terminal may send out modulated target communication light.