We bring forward a novel FBG sensor multiplexing technique based on Petri Net theory and the wavelength/spatial-division multiplexing technique. With this technique, the FBG sensing system not only avoid frequently switching and improve the average response speed, but also is able to enact data acquisition rule according to the priority (PRI), the delay time and the wavelength shift of FBG sensors. Therefore, the smart FBG sensors multiplexing system is more rational and smarter than the conventional WDM/SDM multiplexing technique. To validate the feasibility and advantage of the multiplexing technology, a FBG strain sensing system and theory simulation were proposed. The resolution power of the sensing system is 1με. The average delay time of the technique is lower one magnitude order than the conventional ones.