Since the fiber Bragg grating (FBG) sensor networks have been used more and more widely, the requirements for their multiplexing are increasing;however, the FBG multiplexing may lead to spectral overlap. Aiming at the problem that the overlapping spectra could affect the demodulation accuracy of FBG sensor network, an overlapping spectrum demodulation method based on differential marine predator optimization algorithm was proposed. This method adopted the differential evolution algorithm to optimize the individual updating position strategy, which could enhance the ability to jump out of the local optimal solution. 2~4 FBG overlapping spectra were simulated, and 2 FBG overlapping spectrum demodulations were experimentally verified. Furthermore,the performance of the proposed algorithm was compared with the particle swarm optimization algorithm and the marine predator algorithm.Results show that the proposed algorithm can effectively reduce the probability of falling into local optimum, and improve the stability and reliability of the algorithm.