A multi-target vital sign detection system includes a transmitter, a receiver and a processor. The transmitter is configured to transmit a millimeter wave signal to a detection area, and the receiver is configured to receive a reflecting millimeter wave signal reflected by a plurality of targets in the detection area. The processor is configured to: generate signal strength versus distance data by analyzing the received reflecting millimeter wave signal； perform an extreme value reserving process to generate signal extreme value versus distance data； perform a peak search algorithm to obtain a peak list including a plurality of peak values and a plurality of corresponding peak distances； generate a distance array including a plurality of distance variables； and perform a vital sign detection algorithm to generate multiple sets of vital sign data.
