Oral cancer patients who receive tumor ablation and reconstruction surgery will encounter a number of challenges and complications during treatment course. One of an uncommon complication is intestinal ischemia. Ischemia affecting the small intestine is generally referred to as mesenteric ischemia, while ischemia affecting the large intestine is referred to as colonic ischemia. Acute intestinal ischemia accounts for 60 to 70 percent of cases of mesenteric ischemia and results in high mortality rates that can exceed 60 percent. We present a case of oral cancer patient who received operation, and septic shock struck on him 7 days after operation. Infection source favored intestinal ischemia. After emergency surgical intervention, the patient finally survived. This case report highlights on the etiologies and diagnosis of intestinal ischemia.