Abstract: Objective: Assessing the correlation between MCTSI score combined with D-dimer detection value and the clinical prognosis in patients with acute pancreatitis. Methods: 150 acute pancreatitis patients admitted to our hospital from August 2016 to January 2018 were collected. The plasma D-dimer detection value was recorded on the first day after admission. The CT enhancement scan was performed on the 5th to 7th day. According to the MCTSI standard, the combined detection value of MCTSI score and plasma D-dimer detection value was obtained by Logistic regression equation. MCTSI score, D-dimer detection value and combined detection value were analyzed by ROC curve. Results: There were significant differences in plasma D-dimer detection value and clinical prognosis among mild, moderate and severe acute pancreatitis patients (P<0.001). The D-dimer detection value in severe patients was significantly higher than that in mild and moderate patients (P<0.001). The combined detection value of MCTSI score and plasma D-dimer detection value obtained by Logistic regression equation is more effective in predicting organ failure than using MCTSI score and plasma D-dimer detection value alone, and it has the highest correlation coefficient with the length of hospital stay. MCTSI score combined with D-dimer detection value has high clinical reference value for clinical prognosis of acute pancreatitis patients. Conclusion: According to the combined evaluation of MCTSI and D-dimer detection value, we can understand the clinical prognosis of acute pancreatitis patients, which has a high clinical reference value.