Abstract: The popular way of understanding Rawls' principles of justice is from the perspective of liberalism tradition, that is, he wants to reconcile the freedom and equality in liberalism tradition, which are independent values based on moral man. This paper tries to put forward a new perspective that is different from this perspective, pointing out that equality is the public nature of inter-subject relations, it is not a "value", and does not conflict with freedom. This perspective is based on Rawls' concept of society as a system of fair cooperation. From this perspective, a new understanding of the principles of justice will be gained.