非自杀性自伤（non-suicidal self-injury, NSSI）是儿童青少年常见的心理行为问题，也是自杀行为的重要预测因素。研究表明，情绪调节障碍、冲动控制缺陷、精神疾病共病及家庭与社会环境逆境等可增加儿童青少年发生NSSI的风险，而家庭、学校与同伴支持可对该行为发挥保护作用。其生物学机制涉及遗传与表观遗传易感性、应激反应及内分泌紊乱、阿片系统与疼痛调节功能异常、免疫炎症失衡，以及情绪调节、执行功能、奖赏加工相关神经通路异常。该文系统综述儿童青少年NSSI的相关影响因素及生物学机制，以期为NSSI的早期识别、预防及干预提供参考。

Non-suicidal self-injury (NSSI) is a common psychological and behavioral problem among children and adolescents and an important predictor of suicidal behavior. Studies indicate that emotion regulation difficulties, impaired impulse control, psychiatric comorbidities, family adversity, and adverse social environments increase the risk of NSSI, while family, school, and peer support exert protective effects. The biological mechanisms underlying NSSI include genetic and epigenetic susceptibility, stress response and endocrine dysregulation, abnormalities in the opioid system and pain modulation, immune-inflammatory imbalance, and dysfunction of neural circuits related to emotion regulation, executive function, and reward processing. This review systematically summarizes the influencing factors and biological mechanisms of NSSI in children and adolescents to provide a reference for early identification, prevention, and intervention of NSSI.