After World War II, humanism witnessed significant development due to plenty of social needs; it serves as the theoretical foundation for modern positive psychology. Positive psychology was formally named in 1998, leading to a wave of research in the West. Within the framework of positive psychology, individuals can find plans for describing and understanding a fulfilling life. Given this, three related topics are put forward: positive subjective experiences, positive individual traits, and positive social relationships. This article elaborates on these three topics and explores the model of well-being proposed by positive psychology. At the end of the research paper, many practical applications of positive psychology are listed.