The international community is widely divided on the validity of surrogacy, which has led to the phenomenon of cross-border surrogacy conflicts and triggered the application of public order reservation on the issue of cross-border surrogacy and recognition of foreign surrogacy judgments. In the process of applying public order, the judges of various countries are prone to abuse their discretionary power due to the rigidity of the connotation and theory of public order, and the unclear standard of invoking public order, which interferes with family life and is detrimental to the protection of children. This paper argues that in the parent-child relationship of cross-border surrogacy, public order reservation and protection of children's interests are equally important issues, and cross-border surrogacy judgments should strike a reasonable balance between public order reservation and the principle of the best interests of children. Not only it is necessary to enrich the theory of public order reservation and improve the rules of its application, but the principle of the best interests of the child should be implemented to the greatest extent possible to protect the interests of the surrogate child.