With the rapid development of economy, it brings increasingly fierce market competition as well as continuous innovation of business models and upgrading of industries. In order to achieve rapid scale expansion, strategic opportunities, synergies, and management efficiency, companies often use M&A to meet their needs for rapid development. In recent years, the number of companies involved in M&A activities in China has been increasing, and both M&A activities and the amount involved have seen a significant increase. The large number of M&A transactions has brought about a dramatic increase in goodwill assets. The proportion of the total assets of an enterprise is becoming higher and higher, and it has gradually become the focus of attention of the management and investors, while the subsequent accounting treatment of consolidated goodwill has become an important topic of accounting theory and a hot topic in the capital market. Since the implementation of the new accounting standards in China in 2007, the subsequent accounting measurement of goodwill has been changed from the straight-line amortization method to the impairment test method. With the increase in M&A activities and high M&A premiums, the risk of future impairment of large amounts of goodwill is hidden behind the increasingly large goodwill assets in the A-share market, and the potential risk and possible impact of goodwill impairment has become a hot topic of discussion in academia and the capital market. The value relevance of accounting information is primarily a predictive link that exists between an enterprise's accounting statement information and securities market activity. The value relevance of goodwill and goodwill impairment has significantly increased after the change of the subsequent measurement of goodwill from the amortization method to the impairment method, mainly because the impairment measurement of goodwill has a stronger predictive effect on a company's profitability and future cash inflows, which can significantly affect market participants' expectations of a company's value. With this as the background, the purpose of this paper is to investigate whether goodwill impairment is value-relevant, whether corporate goodwill impairment affects corporate stock prices, and to further analyze the mechanism of its impact.This paper conducts a regression analysis with the data of Chinese A-share listed companies from 2011 to 2021. The theoretical analysis and research hypotheses are based on the efficient market hypothesis, decision usefulness theory, principal-agent theory, information asymmetry theory, signaling theory, and surplus management theory; an empirical model is constructed based on the Ohlson price model, and moderating variables are introduced to discuss the impact of corporate equity structure and internal control on the relevance of goodwill impairment value from the perspective of equity structure and corporate internal governance. The results of the study show that (1) the impact of goodwill impairment on stock prices is negative. (2) The degree of equity concentration has a moderating effect on the value relevance of goodwill impairment, and the effect of goodwill impairment on stock price is enhanced when the degree of equity concentration increases; (3) The degree of equity checks and balances has a moderating effect on the value relevance of goodwill impairment, and the effect of goodwill impairment on stock price is enhanced when the degree of equity checks and balances increases. (4) The proportion of management's shareholding has a moderating effect on the value relevance of goodwill impairment, and the impact of goodwill impairment on stock prices is enhanced when the proportion of management's shareholding is increased. (5) The proportion of institutional investors' shareholding has a moderating effect on the value relevance of goodwill impairment, and when the proportion of institutional investors' shareholding increases, the impact of goodwill impairment on stock prices will be enhanced. (6) The proportion of independent directors has a moderating effect on the value relevance of goodwill impairment, and when the proportion of independent directors increases, the impact of goodwill impairment on stock prices will be enhanced. (7) Internal control has a moderating effect on the value relevance of goodwill impairment, and the impact of goodwill impairment on stock prices is enhanced when the quality of internal control is improved.This paper reveals the important paths through which corporate goodwill impairment affects corporate stock prices. A targeted study of the influencing factors is conducted with the perspective of equity structure and corporate governance within the firm. This is an important theoretical reference for improving the quality of goodwill impairment information, improving data accuracy, and subsequently increasing the strength of trust and utilization of goodwill impairment information by stakeholders.