This article takes A-share market M&A cases from 2010 to 2022 as samples to investigate the influence mechanism of related M&A, goodwill impairment and the risk of the stock price crash, and the differences of the above effects in different industries. The study finds that related M&A presents a higher premium rate in the asset-light industry, which deepens the risk of goodwill impairment and brings a greater stock price crash risk. Further research shows that frequent related M&A behavior deepen the positive correlation between goodwill impairment and stock price crash risk. The enhancement effect is pronounced in the asset-light industry. This paper deepens the comprehensive understanding of related M&A and enriches the related research on goodwill impairment, which makes it specific reference value to small and medium investors.