Latent Dirichlet Allocation model is used to mine the theme, 144 new energy vehicle related policies at two levels of the state and six provinces in the central region are taken as the research objects. And a quantitative analysis is made in terms of high-frequency vocabulary, theme intensity and annual changes of hot themes. The results show that the national level themes are mainly energy-saving development, power battery recovery, etc.; the themes of the six central provinces are mainly public facilities construction and financial subsidies; the national level promotes the development from the overall perspective of green development and energy conservation and environmental protection, while the central six provinces pay more attention to the promotion of financial subsidies; the new energy vehicle industry policy system is relatively perfect, but the hierarchical politics There are some problems such as lack of interaction and neglect of conduction and penetration.