Abstract: The western mining area in China has good coal deposit conditions,high mining intensity and serious damage to overlying strata,which can induce goaf collapse,ground fissures and ecological destruction on the surface.Moreover,the spontaneous combustion of residual coal also occurs,which can threat the safety of coal mine production.To collect the information of mining induced ground fissures quickly,timely and accurately,a method to identify ground fissures was proposed based on an unmanned aerial vehicle (UAV) equipped with an infrared camera and image edge detection technology.Taking the working face No.12401 of the Shangwan coal mine in Shendong mining area as the engineering background,a round the clock monitoring of ground fissure development area above the working face was conducted,and some infrared images at different times were obtained.The temperature information of fissure,sand,vegetation and the length of fissure in infrared images at different times were statistically analyzed.A variety of edge detection methods and the proposed improved edge detection method were used to detect the fissures in the typical infrared image,and the fissure detection results were evaluated.By comparing and analyzing the results of fissure detection at different times,the optimal time for identifying the ground fissures by UAV infrared remote sensing technology under the conditions studied in this paper was given.The results show that an UAV equipped with an infrared camera and edge detection technology can be used to identify mining induced ground fissures effectively.Compared with the daytime,the ground fissures are easier to be identified at night,especially during 3:00 am and 5:00 am.The Pratt’s figure of merit (PFoM) value of the improved edge detection method is 0.571.Compared with the other edge detection methods,this method has a good detection effect for ground fissures.From 1:00 am to 5:00 am and 7:00 pm to 11:00 pm,the results of fissure detection are better than those of other times.The noise in the detection results is less,and the edges of the fissures are clearly prominent.Especially the fissures detection effect at 3:00 am and 5:00 am are the best.