External transport link is one of the main factors of the urban transformation and sustainable development toward the resource-exhausted cities. Taking 69 resource-exhausted cities as the object of study, this paper characterizes the urban external transport link level by daily accessibility indicator and employs the industrial substitution industry output value to reflect the economic transformation effects. In addition, the correlation analysis and geodetector and panel data model are utilized to address the relationship between accessibility and the effectiveness of urban economic transformation and to reveal the mechanism of accessibility on the economic transformation rules and characteristics of the resource-exhausted cities. The result shows that the overall accessibility level toward the 69 cities is medium and has a positive effect on the urban industrial substitution industry scale and efficiency development. The accessibility is one of the key factors affecting the alternative industries in these resource-exhausted cities. Furthermore accessibility can indirectly promote or hinder the development of resources city economy transformation by influencing the private economy, industrial park economy, fixed asset investment and high-tech industries and so on. Superior accessibility cities usually have stronger capacity for economic transformation and development. Moreover good accessibility will not only help the alternative industries to obtain necessary resources such as science and technology, intelligence, capital, labor force, market and information, but also create favorable conditions for regional industrial cooperation, industrial transfer and investment attraction to meet the internal needs of the alternative industries layout. On the contrary, the alternative industries with the lowest accessibility and far away from the economic center cities generally tend to have sluggish development, weak economic transformation and strong dependence on traditional resource-based industries. Meanwhile, the contribution of accessibility to the development pattern of economic transformation has been gradually strengthened. In view of this, the resource-exhausted cities in different regions are suitable to adopt different transformation models and differential support policies in combination with different levels of accessibility.