A millimeter wave radar-based non-contact real-time vital sign monitoring system and method. The monitoring system comprises: a millimeter wave transceiving module (1), a real-time signal acquisition module (2), a real-time signal processing module (3), and a visualization module (4). The millimeter wave transceiving module (1) is used for transmitting millimeter waves and receiving echo signals thereof; the real-time signal processing module (3) is used for extracting respiratory signals and heart rate signals by means of clutter suppression; and the visualization module (4) is used for performing waveform fitting on the respiratory signals and heart rate signals, and displaying, by means of a visual interface, the position, respiration, and heart rate of a subject in real time. The clutter suppression effectively overcomes the effect of environmental noise, such that the accuracy of the monitoring system is improved. In addition, the respiratory signals and heart rate signals are fitted by means of an iterative algorithm to visually display relevant waveforms and monitoring results.