The invention discloses a method and a device for flame detection based on video image analysis. The method includes: firstly, adopting a video image acquisition unit to acquire video images in a monitoring area, judging a type of a current frame image by the aid of an image information judgment unit, and adopting different processing modes for subsequent processing according to different image types; secondly, extracting a suspected flame area of the current frame image by the aid of a suspected area extraction unit, and removing false areas which do not match conditions by the aid of a screening unit; thirdly, adopting a match updating unit for match updating operations of suspected areas kept after screening; finally, adopting a judgment alarm unit to judge whether match times of each historical suspected area reaches a threshold or not so as to judge whether the suspected areas have fires or not. By the method and the device for flame detection based on video image analysis, classified judgment is carried out according to different features of flames in daytime and at night, so that alarm accuracy is greatly improved.