Abstract: In order to develop the application of time-of-flight algorithm in fire detection and simplify the algorithm to improve detection rate and accuracy, according to the time-of-flight-depth-map method, considering with the characteristics of depth map of fire flame, fire flame identification algorithm based on variation rate of time-of-flight-depth-map was designed. Several groups of fire flame identification experiments, including n-heptane flame, ethanol flame, paper flame, lamplight interference and pedestrian interference test, were carried out with 3-D depth camera acted as main equipment. The captured maps were processed and computed. A simplified algorithm was proposed for fire flame identification which was used to analyze the characteristics of depth map, frequency spectrogram, concentration ratio and area fluctuation of fire flame. The results indicate that the identification precision rate is greater than 91.5%, and the misrecognition rate is less than 3.8%. Fire flame could be efficiently identified with this algorithm.