Objective To propose a non-contact biological radar signal processing algorithm for identifying human and animal so as to enhance the accuracy and robustness of identification. Methods An ultra-wideband (UWB) radar on a chip with 7.29 GHz center frequency and 1.4 GHz band width was utilized to collect radar signals from human and animals in free-space condition. After signal preprocessing of direct current filtering, low-pass filtering, adaptive filtering, an improved feature of respiratory and heartbeat energy ratio was extracted from aspects of frequency and energy. Results Human and animals identification results showed that compared with the traditional respiration and heartbeat energy ratio characteristics, the proposed feature in this paper of improved respiratory and heartbeat energy ratio owned higher accuracy and higher robustness, and could eliminate the phenomenon of identification and misjudgment caused by individual differences. Conclusion The improved feature of respiratory and heartbeat energy ratio extracted from UWB radar signals can identify human and animal targets more accurately. The method can be employed as the underlying technology of the non-contact intelligent health monitoring equipment to help it identify the target, thereby ensuring the accuracy and reliability of the signal source. Thus, it has significant value in applications.