Abstract: Compared with traditional trust mechanism, the credit scoring mechanism for the digital platform is a new one that is created and implemented by the platform and develops by the participation and use of the platform users. For such mechanism, this study indicates that it is "secretly autonomous" in the platform in its generation, use and relief measures, and is essentially the conflict between self-interest and public interest and that between autonomous and legal orders. Then, this study puts forward that such "secret autonomy" may bring potential problems: the credit anxiety out of non-disclosure of scoring standards, the credit manipulation due to unsupervised scoring activities, and the failed network trust mechanism owing to unable to verify the scoring results. When making regulations on credit scoring mechanism, we may trap in the dilemma of lacking efficient platform autonomy, regulation of private rights, and supervision by public power. As a result, this study proposes that we can make progress in the regulation path, mode and tool, and form of responsibilities. To make it further, we can take the construction of order as the regulation path and the participant collaborative governance as the regulation mode, by adopting the information tools and the responsibility mode of limiting qualification of market subjects, to eliminate the potential problems of "secret autonomy", improve the scoring regulations and activities and ensure the credit scoring mechanism for the digital platform works efficiently.