In this paper, a method for optical localization of discharge sources based on a multi-normal photoelectric array is proposed. The core idea is to use the response of the photoelectric sensor to the ionizing light signal emitted by the partial discharge to achieve angular localization. The main analysis and synthesis steps include: firstly, testing the sensitivity of the photoelectric sensor to capture the discharge light signal; secondly, analyzing the principle of light source tracing based on the normal vector of the 3-dimensional sensor and giving the calculation steps of angular localization based on the proportional response; then, giving the cooperative localization method based on multiple normal vectors to improve the accuracy of light source localization. Finally, the validity of these obtained results is verified by a simple experiment test.