The phase consistency between different channels of the fiber laser sensor system has great effect on beamforming and target locating in the detection of underwater acoustics and seismic wave. So it is important to study the phase consistency between different channels. The factors influencing the phase consistency of the fiber laser array system based on dense wavelength division multiplexing (DWDM) and phase generated carrier (PGC) demodulation are analyzed. The analysis and corresponding calculations show that the influence of the sensor′s wavelength difference can be neglected. An experiment is carried out on two channels distribution-feedback (DFB) fiber laser sensor array system to demonstrate the analysis, The results show that the system has high phase consistency in the situation of different sensors and the results are in accordance with the theoretical expectations.