Frequent financial fraud incidents make domestic and overseas authorities and scholars concern about the quality and efficiency of internal control. Effective internal control can ensure legal compliance of business, improve the quality of financial report, maximize enterprise value and protect the interests of investors. Based on the constituent elements of internal control, this paper analyses the key factors, and proposes measures like enterprise competence, culture, communication and risk prevention to enhance the level of internal control effectiveness and promote sustainable development and stability of capital market.