Abstract: This study aimed to summarize the diagnosis of jejunal diverticulum perforation with hepatic portal venous gas (HPVG) and superior mesenteric vein (SMV) thrombosis using multislice spiral computed tomography (MSCT) and evaluate its curative effect to improve the understanding of this disease. The clinical data, imaging manifestations, treatment, and prognosis of a patient with jejunal diverticulum perforation with HPVG and SMV thrombosis were retrospectively analyzed, and relevant literature were summarized and analyzed. Here, the primary clinical manifestations were persistent abdominal pain and fever. MSCT revealed multiple diverticula in the proximal jejunum. A diverticular wall ruptured and connected to the adjacent SMV branch, resulting in HPVG. Enhanced CT showed thrombus in the SMV. Intraoperatively, multiple jejunal diverticula were observed, of which some showed hyperemia, edema, and exudation. An intraoperative thrombus was observed in the SMV. The pathological manifestations include inflammatory cell infiltration in the jejunal diverticulum and thrombus formation in the SMV. MSCT can clearly diagnose jejunal diverticulum perforation with HPVG and SMV thrombosis and show the exact location of the perforation. Jejunal diverticulum perforation with HPVG and SMV thrombosis suggests that the patient’s condition is critical, and active surgical treatment is needed to save the patient’s life.