The existing literature studies the relationship between institutional investors and the risk of stock price crash from multiple dimensions. Based on the phenomenon that institutional investors hold the shares of several listed companies in the same industry, this paper takes the A-share listed companies in Shanghai and Shenzhen stock markets from 2008 to 2018 as the research samples to explore the relationship between institutional common ownership and stock price crash risk. The results show that: institutional common ownership significantly increases the risk of stock price crash. After a series of robustness tests, the conclusion remains unchanged. The impact mechanism test shows that institutional common ownership improves the stock price synchronization, investor sentiment and stock liquidity, and then aggravates the risk of stock price crash. Further tests show that the higher the product market competition, the more media coverage, and the weaker the protection of regional investors, the positive impact of institutional common ownership on the risk of stock price crash is more significant.