The invention particularly relates to an audio/video combined monitoring method and a system thereof, belongs to the technical field of industrial environment monitoring, and aims to solve the problems in the prior art, for example, the monitoring is only conducted by video monitoring operators on duty, who are easy to be fatigue and hardly identify places with potential safety hazards, moreover, video monitoring is limited by functions and viewing angles, so that the potential hazard cannot be found in time, thereby missing rescue opportunities. The audio/video combined monitoring method uses audio signals and video signals at the same time to conduct environmental monitoring, and guides the operators on duty to selectively observe video windows by using the identification results of the audio signals. The processing method of the audio signals comprises the following steps: (1) feature extraction, (2) model training, (3) sound classification, (4) online study, and (5) hazard rating evaluation.