The construction of safe and efficient logistics transportation routes for hazardous chemicals can effectively ensure the safety of personnel and property. In this paper, the transportation distance and transportation risk in the distribution process of hazardous chemicals are taken as the optimization objectives. Besides, considering the risk impact of the hazardous chemicals’ weight change on the distribution route planning, a bi-objective optimization model that minimizes the distribution distance and transportation risk was constructed. Then, the traditional ant colony algorithm was improved by selecting the non-dominated solutions from the single solution results of the ant colony algorithm, and the transportation risk and transportation distance objective of the selected optimal non-dominated solution were extracted, to calculate the weights of the two and integrate them into the update process of overall calculation information. Finally, the simulation test method was used to compare and analyse the difference in route planning between the traditional risk measurement model and the improved one of hazardous chemicals transportation. The experimental results show that the improved risk measurement model can better distinguish the route with less risk. It also has stronger algorithmic optimization abilities and sensitivity to population exposures, so as to provide a variety of planning routes for personnel and meet the diverse needs of transport distances and transportation risks.