The invention relates to a road network congestion propagation situation prediction method and system based on an infectious disease model. The method comprises the following steps of acquiring road network data at the current moment, performing road section division on the road network data according to the road section types to obtain a road section set of each road section type, wherein the road section types comprise a congested road section, an unblocked road section which is easily propagated and congested and an unblocked road section which is not easily propagated and congested, according to the road section set of each road section type, based on an infectious disease model, predicting a road network congestion condition at each moment within a set duration to obtain road networkprediction data, wherein the road network prediction data comprises a road section set of each road section type corresponding to each moment, acquiring a road network congestion propagation evaluation index, wherein the road network congestion propagation evaluation indexes comprise a propagation scale, a propagation duration and a propagation speed, and in combination with the road network congestion propagation evaluation index, analyzing the road network prediction data to obtain a road network congestion propagation situation at the current moment. The real-time performance of road network congestion propagation situation prediction can be improved.