In the road transportation industry, the high risk of default by enterprises will have a serious impact on consumer interests and market order. To improve the scientific nature of the credit evaluation of road transportation enterprises, this paper establishes a credit evaluation model based on the combination weighting method, considering the information volume, volatility, and difference of the road transportation enterprises data and using normalized constraints of maximum variance to determine the combination weights. The model fully considers the degree of difference between the indicators and makes up for the deviation of the single weighting method. Finally, the paper makes an empirical analysis of 115 road transportation enterprises in a certain province of China and verifies the rationality of the combination weighting model. The results show that the credit level of a road transport enterprise in a certain province is at a medium level. Strengthening the supervision and examination of the management, qualification, and safety production capacity of the enterprise can further improve the credit level of the road transportation enterprise.