In large fiber Bragg grating(FBG) sensor networks, due to the limited bandwidth of light sources and the large number of FBG sensors, the problem of spectral overlap will occur. Therefore, improving the reuse ability has become a key problem in the design of sensor networks. In this paper, the experiment and simulation analysis of multi-FBG transmission system are carried out by combining spectral reuse with quantum particle swarm optimization(QPSO) algorithm. Compared with the traditional particle swarm algorithm, the parameter setting of the QPSO algorithm is relatively simple, and the ability of particle search for the optimal solution is greatly improved. The paper analyzes the demodulation results of QPSO algorithm and adaptive mutation quantum particle swarm optimization(AMQPSO) algorithm, and compares the demodulation accuracy and time of the two algorithms. The demodulation error of AMQPSO algorithm in multi-FBG reuse system is not more than 3 pm, the accuracy of temperature measurement is up to 0.3 ℃, and the demodulation time is not more than 5 s. It solves the problem of partial overlap and complete overlap in multi-FBG system.