The complexity of language contact and intercultural communication has generated various issues in relation to language use and education. As one of the many Chinese dialects ("fangyans"), the Chaoshan dialect ("Teochew") has been affected by the extensive promotion of Putonghua, the key lingua franca across China, and English, the lingua franca for international communication. Therefore, it is worth exploring the current situation and sustainability of Teochew from the perspective of multilingualism. This study used a questionnaire and interviews with local Chaoshan people as the research instruments with which to investigate the perspective of family language policy, the usage frequency of Teochew on different occasions and among different groups, parents' and students' levels of Teochew mastery and the factors influencing the family language policy of Teochew. It also aimed to determine the participants' first-language practices and attitudes towards Teochew. The findings reveal that the majority of the participants have positive attitudes regarding the inheritance and development of Teochew; however, the future of sustainable development shows a weakening trend. The paper concludes by emphasising the significance of maintaining Teochew as one of the many fangyans in China, in addition to the "lingua franca," as seen from a multilingual perspective.