A detection method of key road-sections based on Ricci flow is provided and includes: building a weighted road network according to static road network data and actual traffic flow data; calculating initial values of Olivier Ricci curvature at different times; obtaining a weight system of making edges of the weighted road network be with a same value of Olivier Ricci curvature by a Ricci flow iterative process; and calculating direction and degree of weight change of each of the edges corresponding to road-sections, and setting a threshold to extract key road-sections. The method solves problems that the existing methods analyze the key road-sections from the topological structure of the road network without fully considering the actual distribution and transmission characteristics of the traffic flow in the network, is simple and easy; and the detection result more meet the traffic distribution and the flow of the actual road-sections.