Under the framework of agency theory, this paper studies the impact of tax aggressiveness on corporate financing constraints, and analyzes the impact of independent directors on their relationship according to directors dual functions. The results show that there is a positive correlation between tax aggressiveness and financing constraints, that is, tax aggressiveness will lead to an increase in financing constraints. Independent directors can help reduce the degree of tax radicalization and weaken the positive relationship between tax radicalization and financing constraints. Independent directors with financial expertise can alleviate the situation more. This study provides theoretical and practical evidence for enterprises to better understand the possible economic consequences of tax aggressiveness, give full play to the advisory and supervisory functions of independent directors in the process of tax avoidance, so as to formulate reasonable tax planning and alleviate the financing constraints of enterprises.