In accordance with the multilingual turn and positive turn in the field of applied linguistics in recent years, well-being has become an important concept in foreign language education. As a result, promoting learner well-being is now explicitly deemed as one of the education goals. Triggered by this, some researchers began to explore the positive impact of second language (L2) learning on bilinguals’ well-being. Starting with the multi-dimensional concept of well-being, this article first gives a brief introduction to its theoretical background and components. Then, based on the unique advantages of bilingual learners, the positive role of L2 learning in improving bilinguals’ well-being is illustrated with empirical evidence. Finally, some suggestions are put forward for future research.