目的：本研究主要报道了一例因呕血为首发症状的门静脉系统血栓青年患者，同时对门静脉系统血栓的病因、临床表现、影像学表现及治疗方式进行探讨，提高对门静脉系统血栓的诊治认识。方法：回顾性分析2020-08-02收治的一例门静脉系统血栓导致肠坏死患者的临床资料，针对门静脉系统血栓相关资料查阅文献进行分析总结。结果：根据影像学表现确诊为门静脉系统血栓，予以抗凝、溶栓治疗，后患者病情进展迅速，出现肠坏死，遂予以手术切除坏死小肠，最终患者好转出院。结论：门静脉系统血栓临床上较为少见，致死率较高，由于门静脉系统血栓少部分可导致患者出现肠坏死，需要及时行手术治疗切除坏死肠段，因而临床上早发现、早诊断、早治疗对提高患者治愈率具有重要意义。 Objective: This study mainly reports a young patient with portal vein thrombosis due to hematemesis as the first symptom. At the same time, we discussed the etiology, clinical manifestations, imaging findings and treatment of portal vein thrombosis so as to improve the diagnosis and treatment of portal vein thrombosis. Methods: The clinical data of a patient with intestinal necrosis caused by portal venous system thrombosis admitted on 2020-08-02 was retrospectively analyzed, and the literature related to portal venous system thrombosis was analyzed and summarized. Results: According to the imaging findings, the patient was diagnosed with portal vein thrombosis and was treated with anticoagulation and thrombolytic therapy. After that, the patient’s condition progressed rapidly and intestinal necrosis appeared. Then the necrotic small intestine was surgically removed. Finally, the patient got better and was discharged. Conclusion: Portal vein thrombosis is relatively rare in clinical practice, and the fatality rate is high. A small part of the portal vein system thrombosis can cause intestinal necrosis in patients, so surgical treatment is timely required to remove the necrotic intestinal segment. Therefore, early detection, early diagnosis, and early treatment are of great significance to improve the cure rate of patients in clinical practice.