Abstract: Objective To predict the prognosis in ICU adult critically ill patients by application of Nutritional Risk Screening (NRS2002). Methods The 201 adult critically ill patients at Binzhou City People's Hospital of intensive care unit from January, 2017 to May, 2017, were used investigative research. The patients were scored NRS2002 and APACHEⅡ in 24 hours to complete the score. To give Enteral and/or Parenteral nutrition support.According to the prognosis of patients were divided into death and survival groups, to compare two groups NRS2002 score and APACHEⅡ; Observe there groups APACHEⅡand case fatality rate difference; Analysis the predictive value of NRS2002 and APACHEⅡ on prognosis. Use SPSS 16.0 statistical software for statistical analysis. Results The risk of moderate nutritional risk was 88.6% in critical patients. Death and survival groups NRS2002 and APACHEⅡ comparison difference was statistically significant (P<0.05). Different nutritional risk group APACHEⅡ and case fatality rate comparison difference was statistically significant (P<0.05). There was no statistical significance in the moderate and severe nutritional risk group (P>0.05). NRS2002 with and APACHEⅡ prognosis presented positive correlation, the correlation coefficient r of 0.269 and 0.329, respectively. The two rated ROC curves were 0.644 and 0.682 respectively, and the difference was not statistically significant (P>0.05). Conclusion There are high nutritional risks in adult critical patients. The NRS2002 reflects the severity of the patient's condition, which can predict the prognosis of a critical patient. Early nutritional support can improve patient outcomes.