The mathematic models of the Mach-Zehnder interferometers based fiber-optic distributed disturbance sensor for the multiple disturbances applications were established in accordance with coherent lightwave theory. According to the models, the influences of the multiple disturbances on the location precision of the fiber-optic distributed disturbance sensor were simulated. The relationship concerning the location precision, the amplitude ratio and the distance of the disturbances were presented. The simulation results demonstrate that the stronger disturbance can be located when the amplitude ratio of the multiple disturbances is larger than or equals to 20. The multiple disturbances can be regarded as a disturbance when the distances of the disturbances are less than 100 m. The polarization beam splitters were utilized to eliminate the influence of the polarization induced fading. Then the signal generator produced sine wave, applied to the two piezoelectric transducers simultaneously to simulate the disturbances. The experimental results show that when the amplitude ratio of the two disturbances imposed on the sensing fiber at 5 km and 10 km is larger than or equals to 20, the maximum location error from the strongest disturbance is 200 m. The maximum location error from the 5 km position is 100 m when the amplitude ratio of the two disturbances applied at 5 km and 5.05 km is 1. The numerical simulation results were proved by the experiments and helpful to improve the location precision and reduce the false alarm rate for multiple disturbances applications.