Abstract: The microeconomic consequences of financing constraints have a profound impact on the relationship between audit firms and clients and affect the stability of audit contracts. Based on information asymmetry theory and reputation mechanism, a Logistic model was established by collecting the 2015 to 2018 data of A-share non-financial listed companies, the financing indexes were constructed by applying multiple discriminant method and sequential Logistic regression method, and the relation between financing constraints and audit firm changes was analyzed. The results show that the higher the extent of financing constraint is, the higher the possibility that an audit firm changes, and the priority of choosing the new audit firm is from high reputation to low reputation. After the change of an audit firm, the client would receive a clearer audit opinion. With the industry concentration of the audit firm weakening, the financial condition of the clients improve, but the financing cost and investment efficiency of the client do not significantly change, which indicate that the client changes the audit firm mainly for financing, while the firm does not play the role of corporate governance, because the client might pay for the wanted audit opinion. In addition, the study also found that only the nature of client property rights and audit delay moderate the effect of financing constraints on audit firm change. The findings remind regulators and financial institutions to pay more attention to the potential impact of firm changes.