How to promote common prosperity in the context of high-quality development is an important current issue. However, the bank credit-dominated indirect financing system in China exhibits phenomena such as credit discrimination, credit misallocation, and financial repression, leading to the problem of “difficult and expensive financing”. As a result, an increasing number of real enterprises have ventured into shadow banking. Corporate investment activities and capital allocation are important factors affecting labor income share. Therefore, it is particularly important to study whether the crowding-out effect and profit effect of real enterprises participating in shadow banking business will affect their dependence on labor capital, thereby affecting their share of labor income. This article selects sample data from non-financial and non-real estate listed companies in China’s Shanghai and Shenzhen stock markets from 2007 to 2021. Drawing on the approach of Jiang et al. (2010) and Jiang Xuanyu and Jia Jing (2021), this research employs the natural logarithm of the sum of entrusted loans, entrusted wealth management, private loans, and purchased financial products as a proxy variable for real enterprises’ participation in shadow banking. Labor income share is measured by the ratio of labor remuneration to the added value of corporate factor costs. First, an empirical study is conducted on the relationship between real enterprises’ participation in shadow banking and their labor income share. Second, the study examines mechanisms from three perspectives: industrial investment, R&D investment, and the quality of accounting information. Finally, it considers the heterogeneity of factors such as the proportion of shares held by management, the intensity of media supervision, and employee hierarchy on the fundamental relationship and performs contextual testing. The study finds that participation in shadow banking significantly reduces labor income share for enterprises. Mechanism tests reveal that real enterprises’ participation in shadow banking crowds out industrial investment and reduces R&D investment and accounting information quality, thereby lowering labor income share. Furthermore, when the shareholding ratio of corporate executives is low and media supervision is weak, the reduction effect of shadow banking participation on the labor income share of the enterprise is more significant, and this reduction effect is mainly manifested in ordinary employees. This research reveals, to some extent, the intrinsic logic of promoting common prosperity in China during high-quality development, with both theoretical and practical significance. Theoretically, this topic helps expand research perspectives on factors influencing labor income share and the economic consequences of real enterprises’ participation in shadow banking, providing empirical evidence at the micro level for achieving common prosperity goals, high-quality development of listed companies, and preventing and mitigating major financial risks. Practically, the study demonstrates the necessity for government departments to optimize policy environments for industrial investment, guiding listed companies to return to their main business. Additionally, financial regulatory bodies should continuously enhance the quality of market entities’ information disclosure and improve the market financing environment. Enterprises should focus on strengthening their core business, enhancing R&D investment, and improving accounting information quality as a means to promote sustainable and high-quality development, thereby achieving common prosperity goals.