[目的]总结预防接种后猝死病例原因,吸取工作经验。[方法]根据现场调查、患者接种和死亡表现及尸检报告进行综合分析。[结果]患者按免疫规划要求接受卡介苗接种,实施过程符合要求,患儿病变突然,死亡急速,尸检有胸腺淋巴体质和内脏器官缺氧表现。[结论]患者死因可能是卡介苗接种后引起速发型变态超敏反应,但不能排除由于睡眠时吐奶引起窒息意外。 [Objective] To summarize the causes of sudden death after vaccination and draw working experience. [Methods] According to field investigation, patient inoculation and death manifestations and autopsy reports were analyzed comprehensively. [Results] The patients were given BCG vaccination according to the immunization plan. The implementation process met the requirements. The disease in children was sudden and the death was rapid. The hypothyroidism of the thymus lymphatic system and the internal organs were detected by autopsy. [Conclusion] The cause of death in patients may be caused by immediate post-BCA allergic hypersensitivity but can not be ruled out as a result of asphyxiation due to spit milk during sleep.