Ultra-wideband (UWB) radar has broad application prospects in ultra-close range detection. In this paper, the life signal mode of UWB radar is analyzed, and the signal extraction based on permutation entropy (PE) and empirical mode decomposition (EMD) is proposed. The permutation entropy is calculated for the radar echo data, the target distance information is estimated, and the vital sign signal of the target adjacent distance gate is reconstructed according to PE values. EMD is used to decompose the reconstructed vital sign signal, and the result is that the heartbeat and breathe signals are separated in the time domain. The experimental results show that the method can be effectively applied to the vital sign signal extraction of ultra-wideband radar.