As one of the elements of the law, the principle of law plays a vital role in al aspects of legislation, justice, law enforcement and law-abiding. This article will take the classic case"Luzhou Legacy Case"as an example. In this case, the court applied the principle of public order and good customs to make judgments, which caused a series of disputes. The principle of public order and good custom is one of the basic principles of our civil law. Its main content is to appropriately restrict the free will of the parties and realize the unity of personal interests and social interests. Exploring the reasons for the judiciary's application of the principle of public order and good custom, and analyzing the legality of the controversial Huang's bequest, and finding out the inadequacies of the case and the best solution. On this basis, we will consider the standards and methods of judicial application of the principle of good order and good custom, and make some suggestions on the system of reservations in the Law of Succession, and provide countermeasures for similar cases in the future.