In the face of the rising prevalence of mental illness, people have shown increasing concern for the treatment of mental illness. Due to the high cost and long duration of traditional psychological treatment, scholars at home and abroad have begun to show a strong interest in the prevention of mental illnesses, so prevention based on the mental health dimension has been widely studied and comprehensively promoted in recent decades. Although there is no lack of research scholars in China to propose some preventive interventions on mental health, there is still a lack of systematic research and elaboration on the concept of psychological prevention applied to the field of mental health, so people are still unclear about the relevant concepts and applications of preventive psychology. The purpose of this paper is to provide an overview of domestic and international research on preventive psychology, present the historical background of preventive psychology, the concept of tertiary interventions, and the possible areas of future application, and then discuss the current developmental dilemmas and propose corresponding strategies to deal with them. It enables domestic research scholars and relevant staff in the field of preventive psychology to have a clearer understanding of the field.