Abstract: Objective: To study the quantitative multi-parameters of CT energy spectrum imaging of pancreatic ductal adenocarcinoma by using enhanced CT energy spectrum imaging, and to explore the parameter characteristics and potential application value of CT energy spectrum imaging of pancreatic ductal adenocarcinoma. Methods: Retrospective analysis was performed on 61 patients with pancreatic ductal adenocarcinoma confirmed by pathology, all of whom underwent enhanced CT scan of advanced arterial and portal vein phase. Single energy CT value, Effective atomic number (Effective-Z), iodine (water) base value and water (iodine) base value of pancreatic cancer lesions and pancreatic parenchyma were recorded. Paired t test (normal distribution) or Wilcoxon signed-rank sum test (non-normal distribution) were used to compare the differences of the above CT energy spectrum imaging parameters between the late arterial period and portal vein period, pancreatic cancer and pancreatic parenchyma, and to plot the corresponding energy spectrum curves. Results: The single energy CT value of pancreatic ductal adenocarcinoma in advanced arterial stage was significantly lower than that in peripheral normal pancreas. The single energy CT value of pancreatic ductal adenocarcinoma in portal vein stage was higher than that in arterial stage and lower than that in peripheral normal pancreas. The lower the low energy segment is, the more significant the difference is. The higher the energy segment is, the smaller the difference is. There were significant differences in single energy CT value, paired base substance iodine (water) base value and Effective-Z corresponding homogenization concentration between pancreatic ductal adenocarcinoma and pancreatic parenchyma in arteriovenous phase, while there was no significant difference in water (iodine) value. Conclusion: The dual-phase enhanced energy spectrum parameters of CT imaging of pancreatic ductal adenocarcinoma have certain characteristics. The single energy CT value, iodine (water) base value and effective atomic number of pancreatic cancer in arteriovenous phase were lower than those in corresponding pancreatic parenchyma, and those in arterial late phase were lower than those in portal vein phase. The lower the energy segment, the more obvious the difference. The comprehensive application of multi-band and energy spectrum multi parameter imaging is helpful to improve the CT density resolution of pancreatic ductal adenocarcinoma, and has the potential value of providing image information for early diagnosis of small pancreatic cancer.