This paper selects A-share listed companies from 2009 to 2019 as samples, takes internal control as intermediary variable, and discusses the influence of major shareholders' equity pledge on listed companies' financing constraints, and conducts grouping research based on the nature of property rights. The research shows that the pledge of major shareholders' equity will aggravate the degree of financing constraint of listed companies, and the greater the pledge ratio, the higher the degree of financing constraint; Equity pledge has a negative impact on the internal control construction of listed companies, and the higher the pledge rate, the more serious the damage to internal control; The higher the quality of internal control, the better it can alleviate the positive effect of equity pledge on financing constraints, that is, internal control plays a part of intermediary effect in the influence of equity pledge of major shareholders on financing constraints, and this effect is more significant in non-state-owned enterprises. Starting from internal control, this paper studies the relationship between the equity pledge of major shareholders and financing constraints, which not only enriches the related literature such as the economic consequences of equity pledge and financing constraints, but also provides a new direction and ideas for alleviating the financing difficulties caused by equity pledge.