Based on Altera′s 32 bit embedded soft-core processor Nios Ⅱ, the parallel wavelength demodulation system of a four-channel distributed fiber Bragg grating sensor network was designed. The optical system and hardware circuit for demodulation system were designed specifically. Field-programmable gate array(FPGA) is the core of the hardware circuit, which can collect and process the photoelectric signal voltage transformed to rectangular voltage pulse. The hardware circuit can communicate the signal to the computer through the universal asynchronous receiver transmitter(UART) and universal serial bus(USB). The computer can display a dynamic fiber grating wavelength demodulation process and calibrate the Bragg grating center wavelength. The system can demodulate accurately hundreds of outside signals at one time. Compared with other wavelength demodulators with the same functions, it has many advantages, such as flexibility, stabilization, easy maintenance, high-speed, high-precision, and so on. The wavelength demodulation system can be used extensively in large-scale multipoint monitor engineering. At last, an example of wavelength demodulation and calibration is given and precision can reach to ± 2 pm.