A novel technology for security system was proposed based on phase carrier modulationdemodulation in this paper, to realize the multiplex of the white light interference system. In several sensing terminals of the single core feedback white light interference system, there are several phasemodulators which worked at different frequencies. The trigger signal in the different interference subsystems could be separated by phase modulation technology. The signals of the different interference subsystems could be demodulated by phase demodulation technology to have the independent time signal of the different interference subsystems. This method adopted fiber to sense certain environment vibration, obtained the vibration signal using whitelight interferometry, and then located the vibration zone by means of phase carrier multiplexing. Theoretical analysis and experimental results show that it can realize the share of interference system of different sensing terminals based on the technology of phase carrier multiplexing. This technology can decrease the complexity of the security system and reduce the system cost. This method is able to monitor the vibration and locate the intrusion zone in realtime rapidly, effectively and sensitivity. Therefore this technology can be applied in large area and long distance multiple zone intrusion detection systems.