The invention relates to photon interference, in particular to a device and a method of measuring mutual correlation of different light fields based on photon interference. Through the device and themethod, the problem that it is difficult to distinguish chaotic light, coherent light and intensity-fluctuant coherent light currently is solved. According to the specific scheme, the method mainly comprises the steps that a chaotic laser light field, a coherent light field and a broadband noise light field respectively enter an optical fiber isolator, and the optical fiber isolator makes sure toform light unidirectional transmission; the three light fields then enter a non-equilibrium Michelson interferometer, formed by coupling of an optical fiber and a free space, for photon interference;and the number of photons in two output ports of single-photon detectors is collected, distribution of photon time difference of arrival is subject to statistical analysis, and photon mutual-correlation characteristics of the different light fields can be distinguished according to obtained different interference second-order mutual-correlation curves. Through the method, the chaotic light, the coherent light and the intensity-fluctuant coherent light can be distinguished efficiently, the experiment device is high in measurement precision, and the distinguishing effect is obvious.