Abstract: Video based fire detection(VFD) is a convenient, low-cost method widely used in fire detection. However, it's not credible enough to distinguish true fire from possible disruptors by traditional fire features. This paper extract two new features to analyze the time series behavior of fire based on the motion of edge pixels. The inter frame behavior of edge pixels is regarded as a nonuniformty constrained deformation procedure. Combined with HMM and additional geometric features to distinguish true fire from possible disruptors, the accuracy of fire detection is greatly improved and the false alarm rateis efficiently reduced.