Non-suicidal self-injury (NSSI) is a significant global mental health issue. However, whether the deficit in value-based decision-making processing is the consistently key mechanisms of NSSI across studies with heterogeneous decision-making tasks remains uncertain. Hence, we reviewed literature on value-based decision-making and its moderating factors in NSSI, and then conducted a meta-analysis on studies in NSSI, specifically with Iowa Gambling Task. In total, 31 studies with 8417 participants aged from 8 to 50 were included in the systematic review of and 8 studies with 657 participants aged from 10 to 37 included in the meta-analysis. We found consistent impairments in value-based decision-making processing among individuals who engage in NSSI. Importantly, age is a significant moderator, with adolescents with NSSI performance worse, exhibiting increased reward sensitivity and preference for immediate rewards compared to other age groups. These results suggest the important role of value-based decision making in NSSI behaviors, especially during the development of adolescents. Our work provides new insights and integrative evidence for decision-making based prevention and intervention of NSSI.