Abstract: The formal promulgation of“the Law on the Prevention and Control of Soil Pollution”marks that the target of prevention soil pollution in China has changed from "current situation control" to “risk early-warning”. Therefore, it is of theoretical and practical significance to carry out regional soil heavy metal risk warning research. Based on the soil survey data of a grain-producing county along the coast of Taihu Lake in 2015, this study use heavy metal input-output flux model and soil environmental capacity method to calculate the risk probability of five heavy metals in 2030 (15 years later) and 2050 (35 years later). The results show that atmospheric dry and wet deposition becomes the main source of  four heavy metals apart from As. Livestock manure, fertilizer input and irrigation water will also affect soil heavy metal input to some extent. In addition, the three heavy metals of As, Cr and Pb in the cultivated soil of the study area are relatively good, and the risk of Hg and Cd pollution is slightly high, mainly distributed in O town and town P in the middle of the study area. The combination of GIS technology and regional material flow model can provide a good risk warning for different regions and different heavy metal pollution types, which can provide important ideas for the formulation of soil pollution differentiation management strategy.