Corporate financialization is a growing concern in China, and its impact on the main business of real enterprises is a crucial topic. This paper uses data from all A-share non-financial listed companies in China between 2013 and 2022 to establish a dynamic panel threshold model and test the effect of corporate financialization on enterprise performance. The empirical results indicate a threshold effect between the two variables, corporate financialization has both positive and negative effects on main business performance, with a threshold of 5.82%. Additionally, significant heterogeneous results are found for the nature of ownership, asset maturity, industry and regional distribution.