I. Introduction
Social events refer to collective activities such as sports competitions, academic events, and protest events, which are organized, involve specific participants, and occur at a certain time and place [1]. Most social events are a snapshot of social life and threaten society's normal functioning. However, some social events, such as mass protests, often have a large impact on the stability and operation of society. For example, on January 6, 2021, supporters of Donald Trump violently stormed the Capitol building to protest against the election results, leading to the interruption of the session, chaotic scenes, and even causing casualties. Therefore, it is meaningful to examine the causes and causal chain of social events of interest to prevent similar incidents in the future. In the era of big data, obtaining information from the complex and diverse internet has become an important means for people to understand society. However, the quality of information varies greatly. Therefore, developing intelligent algorithms to extract the causal chain of events from the internet effectively is a precious and necessary research work that will assist professionals in clarifying the causes of events.