As the final decision-making body for the settlement of trade disputes, the WTO Appellate Body is known as the "jewel in the crown". However, since 2019, the Appellate Body has been locked out due to insufficient members. The current situation of the Appellate Body urgently needs corresponding reform plans. Based on the analysis of the development process and basic characteristics of the Appellate Body, this article clarifies the main drawbacks that appear in its operation and analyzes the current challenges it faces. The author believes that the resumption of the WTO Appellate Body needs to solve the existing institutional problems. As a temporary arrangement, MPIA, short for Multi-Party Interim Appeal Arbitration Arrangement, cannot completely replace the Appellate Body. Therefore, member states must reach a consensus as soon as possible to maintain the stability of the multilateral trading system and the prosperity of the world economy.