For efficient analysis of mine gas monitoring data to expand monitor system function and realize effective gas pre-warning, the gas concentration pre-warning method based on monitoring data processing was studied. Studying by mine gas monitoring data, its statistical characteristics was abstracted, the intrinsic correlation characteristics of time series consisted by gas monitoring data was also analyzed by using grey relational analysis method. Further, the pre-warning indexes and its thresholds were determined, and the gas concentration abnormal situations could be analyzed, which realized timely and dynamically quantitative pre-warning. The case analysis shows that the method has a better applicability for mine-site gas concentration pre-warning, which can offer the effective decision for daily safe management.