Abstract: This article uses economics ways to analyze the legal settlement mechanism of mass events in three phases of Legislation,law enforcement,judiciary.The author points out that legislation should avoid laws that create mass events,in law enforcement stage laws should be better to do repeated game,emphasize the importance of mass events preventive mechanisms,distinguish rigid or flexible needs to decide between strict and lenient enforcement,increase decision-making costs and external costs in mass events,and in the judicial stage laws should play the role of judiciary.This paper aims to provide useful countermeasures to solve mass events.