Abstract: Doppler radar system utilizes the Doppler effect caused by the human chest movement to extract the vital signal. Based on the established human micro-motion signal model, this paper proposes the complex continuous basis pursuit (CCBP) based vital signal detection algorithm to extract the frequencies of human respiration and heartbeat signal. The proposed CCBP algorithm can extract the vital signal information by using the polar interpolation and the convex optimization problem solving technique, which can accurately estimate the frequency of relatively weak heartbeat signal. Simulation experiment results have verified the validity and accuracy of the proposed algorithm.