Abstract: Blockchain applications have begun to affect economic system, legal system and even the whole social system. As a new social credit consensus mechanism, it will replace the traditional credit mechanism, and then form a new round of empowerment and transformation of the entire society. From the perspective of social system theory, there is a lack of reflectivity and autonomy within the blockchain. At the same time, blockchain has a certain negative externality and expansion tendency, therefore itmay cause disturbance to social systems and their structural coupling. If the expansion tendency of the blockchain is not effectively contained, it will exacerbate the risk of "de-differentiation" of the whole society. Moreover, the risk will endanger fundamental rights. Faced with the impact of blockchain on all areas of society, the legal system responds bylegal regulation. Therefore, on the basis of reflection on the legal regulations of the blockchain, adjustmentshould be made by the leads of the prevention of risks and the protection of fundamental rights.