Objective To explore the relationship between sarcopenia and five clinical types of acute-on-chronic liver failure （ACLF）. Methods From January 2019 to January 2022，a total of 391 patients with ACLF in Beijing You’an Hospital affiliated to Capital Medical University were collected，and the patients were divided into rapid progression （type A，119 cases），rapid recovery （type B，156 cases），slow progression （type C，51 cases），slow recovery （type D，38 cases） and slow persistency （type E，27cases），according to the new clinical type. With the help of CT imaging，nutritional indicators were measured，the incidence of nutritional indicators such as sarcopenia in patients with different types were compared，and the relationship between sarcopenia and five clinical types of new ACLF was explored. Results The incidences of sarcopenia in type A （35 cases，29%） and type C （18 cases，35%） were higher than that in type B （20 cases，13%），type D （3 cases，8%） and type E （27 cases，7%），and the differences were statistically significant （P < 0.05）. The detection rate of myosteatosis patients in type A （36 cases，30.3%） was higher than that in type B （29 cases，18.6%），and the detection rate of myosteatosis patients in type C （11 cases，21.6%） was higher than that in type D （5 cases，13.2%），with statistical significance （P = 0.018）. The detection rate of sarcopenic obesity in type A （16 cases，13.4%） and type C （7 cases，13.7%） were higher than that in type B （11 cases，7.0%） and type D （1 case，2.6%），and the differences were statistically significant （P = 0.047）. Conclusion Nutritional indexes such as sarcopenia were closely related to five clinical types of new acute liver failure. ACLF patients with baseline sarcopenia had poor short-term prognosis （4~12 weeks），and the probability of rapid progress within 4 weeks （type A） or slow progress at 12 weeks （type D） was high. Therefore，nutritional indexes such as sarcopenia should be evaluated as soon as ACLF is diagnosed，so as to improve the overall therapeutic effect，prognosis and quality of life through effective nutritional intervention.