Background: Adolescent non-suicidal self-injury (NSSI) is becoming a serious public health concern worldwide. In recent years, there has seen a significant increase in both the growth rate and cases of NSSI in Eastern countries, such as Japan, India, and China. In China, most schools have a mental health office that comprises mental health professionals (MHPs), who are the first to respond to student mental health problems, which include NSSI. MHPs possess comprehensive knowledge as well as unique insight into adolescent NSSI. However, very few studies on NSSI have incorporated their perspectives. In this work, we seek to add novel insight by conducting a study focusing on adolescent NSSI from the perspective of MHPs.Methods: We recruited a total of 24 MHPs from different schools using purposive sampling and conducted a semi-structured interview on NSSI-related issues. Each interview was voice recorded and lasted ~30 min. A thematic analysis was performed for the responses to study the most common and concerning issues underlying NSSI.Results: We extracted three major themes and eight sub-themes from the interview records, which included (1) the impact of Chinese culture on NSSI (sex-bias discrimination, overly high expectations, and inappropriate parenting style); (2) life events in school (internet use, academic pressure, and romantic relationships); and (3) opinions on the status quo of NSSI in China (ignorance and stigma).Conclusion: Results showed that culturally sensitive influential factors, such as sex-bias discrimination, the imposing of unrealistic expectations for personal achievement, and inappropriate parenting style, should be given more attention to prevent, assess, and intervene in NSSI. Emerging factors of modern society and adolescent lifestyles, such as academic pressure, internet use, and romantic relationships, should also be considered for treatments.