This study reports the diagnosis and treatment of a 26-year-old pregnant woman with severe malnutrition combined with acute pyelonephritis causing sepsis, refractory septic shock and multiple organ failure. A female patient, 26 years old, was admitted to hospital mainly due to "menelipsis for more than 19 weeks, nausea and vomiting for 20 days, fever with fatigue for 3 days". At the end of 19 weeks of intrauterine pregnancy, the patient presented with fever accompanied by urinary tract irritation. Laboratory tests showed elevated inflammatory indicators, and ultrasonography showed bilateral pelvicalyceal dilation. She was diagnosed with acute pyelonephritis, sepsis, acute kidney injury (AKI) and severe malnutrition. After a whole-hospital consultation, the patient was treated with meropenem and vancomycin as antimicrobial therapy, and bilateral nephrostomy drainage was performed simultaneously. After that, the patient suffered a sudden decrease in blood pressure, blood oxygen saturation, and rapid heart rate. Septic shock with multiple organ dysfunction was considered, and she was transferred to intensive care unit (ICU) immediately. After the patient was transferred to ICU, emergency tracheal intubation and ventilator-assisted ventilation were performed. Rapid fluid resuscitation was administered for the patient. While pulse indicator continuous cardiac output (PICCO) monitoring was performed, norepinephrine, terlipressin, and methylene blue were administered to maintain peripheral vascular resistance. Since the patient developed septic cardiomyopathy and cardiogenic shock later, levosimendan and epinephrine were admi-nistered to improve cardiac function. While etiological specimens were delivered, meropenem, teicoplanin and caspofungin were given as initial empiric antimicrobial therapy. Unfortunately, the intrauterine fetal death occurred on the night of admission to ICU. On the 3rd day of ICU admission, a still-born child was delivered vaginally with 1/5 defect of the fetal membrane. On the 6th day of ICU admission, the patient had fever again with elevated inflammatory indicators. After excluding infection in other parts, intrau-terine infection caused by incomplete delivery of fetal membrane was considered. Then emergency uterine curettage was performed and the infection gradually improved. Later the laboratory results showed that the nephrostomy drainage was cultured for Escherichia coli and uterine, cervical and vaginal secretions were cultured for Candida albicans. Due to severe infection and intrauterine incomplete abortion, the patient developed disseminated intravascular coagulation (DIC). Active antimicrobial therapy and blood product supplement were given. However, the patient was critically ill with significant decrease in hemoglobin and platelets combined with multiple organ failure. Thrombotic microangiopathy (TMA) was not excluded yet, so plasma exchange was performed for the patient in order not to delay treatment. The patient underwent bedside continuous renal replacement therapy (CRRT) for AKI. The patient was complicated with acute liver injury, and the liver function gradually returned to normal after liver protection, antimicrobial therapy and other treatments. Due to the application of large doses of vasoactive drugs, the extremities of the patient gradually developed cyanosis and ischemic necrosis. Local dry gangrene of the bilateral toes remained at the time of discharge. In general, the patient suffered from septic shock, cardiogenic shock, combined with DIC and multiple organ dysfunction. After infection source control, antimicrobial therapy, uterine curettage, blood purification treatment, nutritional and metabolic support, the patient was discharged with a better health condition.