Under the background of the rapid development of corporate social responsibility (CSR) in China, this paper investigates the demonstration effect of CSR assurance in board networks. Using the data of A-share listed companies for regression analysis, it is found that the CSR assurance of interlocked enterprises has a significant positive impact on the quality of CSR disclosure.Introducing mandatory reporting pressure as a moderating variable, it is found that external pressures strengthen the demonstration effect of CSR assurance, which provides new empirical evidence for the mimetic pressure theory.