Blockchain technology is one of the most critical emerging technologies. Countries are promoting the development of blockchain technology vigorously. Theoretically, blockchain technology improves the trust between enterprises, reduces information asymmetry, and promotes efficiency. It should promote corporate performance, but analyzing the actual data of Chinese listed companies, contrary to expectation, blockchain technology makes corporate performance decline. We found that this is mainly due to the effect of adverse selection through analysis and empirical tests. The enterprises that use blockchain technology are not accompanied by the increase in R&D expenditure, investment expenditure, and patents. The companies’ abnormal stock return and stock turnover rate have increased. The enterprises with worse performance are more likely to use blockchain to the hype. They can gain a short-term stock return. However, in the long run, the market-to-book ratio of government subsidies and the growth rate of corporate income are declining. Furthermore, the financial constraints are not alleviated as adverse selection only plays a role in the short term. Besides, the heterogeneity tests find that from the prospects of internal governance environment, the higher proportion of the largest shareholder, the better earning quality of the company. The enterprises with state-owned property rights have lower motivations of using blockchain to make an adverse selection. The study also found that the external environment prospects of enterprises with a lower degree of marketization and law environment are more likely to use the blockchain.