The invention discloses a smog detection method based on video analysis. The smog detection method based on video analysis comprises steps of video image data acquisition, video image preprocessing, forward target extraction, flame static characteristic detection, flame dynamic characteristic detection, flame alarm decision, smog static characteristic detection, smog dynamic characteristic detection and smog alarm decision. The method is advantaged in that smog and flame are simultaneously detected in a combined static and dynamic characteristic mode, smog detection accuracy and stability are improved, operation complexity is further reduced, hardware realization is convenient, and the method can be applied to relatively complex environments.