There is great safety risk in the transportation process of dangerous chemicals. In the commercial transportation of dangerous chemicals, it is of great significance to design reasonable transportation path of dangerous chemicals and to minimize the transportation cost of dangerous chemicals under the condition of ensuring transportation safety. This study deals with the transportation scheduling of dangerous chemicals, and constructs a risk and cost assessment model for dangerous chemicals transportation scheduling which aims at minimizing transportation risk and transportation cost. TR model is used to measure the risk in dangerous chemicals transportation scheduling process, a constraint variable considering the distribution order and a symbolic function for improving the solving speed of model are introduced to simplify the existing model. The improved particle swarm optimization (IPSO) is used to solve the proposed model. Based on the simulation experiment, IPSO is compared with the traditional particle swarm optimization (TPSO). The experimental result shows that IPSO has more excellent global search efficiency, obtains a better non-dominant solution, and reduces the transportation risk and transportation cost in the actual transportation after calculation. When the hybridization probability p = 0.6, IPSO proposed in this study has the best effective frontier.