In 2006, the national unified enterprise and individual credit information basic database led by the Central bank was completed and successfully connected nationwide. In recent years, the number of access institutions of the credit investigation system has increased, the scope of coverage is wider, the included information has increased rapidly, and the number of data inquiries has become increasingly large. According to the “Central Bank Credit System Construction Report”, the access institutions of the central bank include banking financial institutions, small loan companies, housing provident fund management centers, insurance companies, trust and investment companies, financial asset management companies, financing guarantee companies and other institutions. Among them, financial institutions account for a large proportion of the access institutions of the central bank, but so far there is no unified standard for the pre-conditions and follow-up management of the access of financial institutions to the credit investigation system. With the increasing importance of credit investigation system, it is necessary to regulate and supervise the financial institutions it connects to. Therefore, this paper studies the path of access of financial institutions to the Central bank’s credit investigation system. On the one hand, it is convenient for the central bank to carry out systematic management of access financial institutions, and on the other hand, it can improve the integrity and accuracy of credit information of the central bank’s credit investigation system. This paper holds that the supervision of big data on the access of financial institutions to the credit investigation system should, on the one hand, improve the legal basis of big data credit investigation, formulate unified data collection standards for access institutions, and on the other hand, formulate unified data preservation and processing rules, and refine data application rules after access. As the largest credit information platform in China, the central bank credit information system plays an important role in improving our country’s credit information system.