In recent years, with the continuous development of computer vision technology and digital image processing technology, flame detection technology based on video analysis has attracted more and more attention. Aiming at the practical significance of video-based flame detection for fire safety, people and national property safety, and the diversity of theoretical basis and influencing factors, the existing video-based flame detection algorithms are summarized. Firstly, this paper introduces the current processing flow of video-based flame detection technology, that is, pre-processing, feature extraction, classification and recognition; secondly, the flame characteristics are analyzed including static features based on single frame and dynamic features based on multi frame, and the typical flame feature extraction algorithms are enumerated. Then, the multi feature fusion, and the classifier classification and the depth learning recognition method for the flame recognition are emphatically summarized. Finally, the difficulties and future development of video-based flame detection technology are discussed in detail.