In order to support synchronous analysis in multi-channel fiber Bragg grating sensing systems, a digital signal processing framework is constructed, which integrates synchronous acquisition, delay estimation, fractional compensation, adaptive denoising, window alignment and spectral peak tracking. The system organizes 16 sensing channels and 48,000 segments of synchronization signals under the strain-temperature coupling condition, and constructs a unified process of sampling control, time registration, feature extraction and cross-channel consistency evaluation. The reference channel selection, phase correlation delay estimation and fractional resampling constitute the link. Combined with threshold denoising and consensus update, the wavelength demodulation is stabilized and the time shift drift under high-frequency sampling is suppressed. Experimental results show that the synchronization error of the proposed method is 0.37 ms, the wavelength demodulation accuracy is 98.9%, the F1-score of peak identification is 97.6%, and the cross-channel variance suppression rate is 21.4%. The hardware and software system maintains the processing speed of 2.8×105 sample points per second, and provides support for the calculation of synchronization signals of multi-channel perception scenes.