With the development of Ultra-Wideband (UWB) technology, UWB radar is widely used in disaster search and rescue operations and hostage rescue situations. Distinguishing between humans and animals is important during such searches. The aim of this paper is to study whether there are differences between humans and animals detected by UWB radar and whether these differences could be distinguished. In this paper, dogs are chosen in order to study their discrimination from humans. For the vital signs detected by UWB radar, which are mainly respiratory activity, dogs are similar to humans and cannot be distinguished from them by the detection methods now in use. Therefore, we propose a new method for distinguishing between humans and dogs by UWB radar detection based on a correlation coefficient of body micro vibration. The results show that there are differences between humans and dogs in correlation coefficients of body micro vibration and optimal correlation coefficients of body micro vibration. The method based on the correlation coefficient of body micro vibration could distinguish between humans and dogs.