In order to meet the demand of high data transmission bandwidth of spectral imaging method using fiber Bragg grating (FBG) in engineering applications for transient temperature and high frequency vibration signal measurement in the gun bore, a high-speed spectral data transfer method based on direct memory access ( DMA) is proposed. A hardware logic of high-speed spectral data transmission based on Zynq is designed, and the FBG demodulation system is built with the principle of spectral imaging, which has realized the synchronous transmission of spectral data by DMA and FBG wavelength demodulation. The results of data transmission simulation experiment and FBG center wavelength demodulation show that the demodulation system can transmit FBG spectrum data at a high speed, the data transmission bandwidth is 320 Mbit / s, the demodulation rate reaches 34 kHz, and the spectrum data transmission has a high stability.