[Purposes] In the study of dangerous goods transportation route optimization, the impact of transportation cost and other risks along the route on transportation are considered simultaneously to strengthen risk control and improve the transportation safety level. [Methods] The data of various risk factors affecting dangerous goods transportation are collected and embedded into the transportation network through a geographic information system (GIS). Then,the concept of risk impedance is proposed as a measure of the risk size of the path. Moreover, a three-objective path optimization is constructd with the minimum total transportation cost, the minimum total risk impedance of the transportation path and the minimum possibility of excessive risk in the local section, which is solve by the designed NSGA-III algorithm. [Findings] Compared with the solution considering only the minimum total transportation cost, although the total transportation cost of the optimized path from this model increases slightly, the total risk impedance of the transportation path and the possibility of excessive risk of the local road section decrease significantly. Compared with the solution that only minimizes the total risk of the route, the total risk impedance of the route and the possibility of excessive risk of the local section have increased. However, the increase is minor, while transportation costs are reduced significantly. [Conclusions] The peoposed model has well considered the economic and safety of transportation and the case of excessive risk in local sections, so it has good generalization and application value.