In recent years, the financialization of entity enterprises has gradually become the focus of theoretical and practical research. Starting from the research perspective of the board informal hierarchy, taking A-share listed enterprises in China from 2009 to 2019 as the research sample, this paper discusses the impact of the board informal Hierarchy on companies' financialization. The results show that: (1) the higher the informal hierarchy of the board of directors, the more intensive the degree of financialization; (2) Whether the chairman is at the highest level of the informal hierarchy and the level of marketization has a significant positive regulatory effect; (3) By decomposing different types of informal hierarchy board of directors, it is found that compared with the difference of social reputation, the informal hierarchy of board corporate association promotes financialization more significantly, while the informal hierarchy formed based on the difference of political capital has no significant impact on financialization; Compared with long-term financialization, the informal hierarchy of the board of directors has a significant positive impact on short-term financialization; (4) From the perspective of impact consequences, the financialization caused by the informal level of the board of directors has significantly improved corporate performance and eased financing constraints. This study helps to deeply explore the causes of micro enterprise financialization, has enlightenment for enterprises to optimize board governance and prevent financial risks, and also provides a certain reference value for government departments to strengthen supervision.