Abstract: Objective: To investigate the value of MRI diffusion weighted imaging(DWI) in the diagnosis of pancreatic examination in patiens with type 2 diabetes mellitus. Methods: 75 patients with diabetic patients were divided into 3 groups according to the duration of the patients, 2 years 2~10, 10 years. At the same time, 25 healthy people were selected as the control group. The diffusion coefficient(ADC) of pancreatic lesions was measured by MRI scan, and DWI scan, and the imaging features of MRI and DWI were observed. Results: DWI examination and measurement of healthy control group and the ADC values of pancreatic lesions in the three groups were(2.00 ± 0.17) × 10^-3 mm²/s,(1.94 ± 0.09) × 10^-3 mm²/s,(1.86 ± 0.13) × 10^-3 mm²/s,(1.77 ± 0.25) × 10-3 mm²/s. Compared with healthy controls, the P values were 0.023, 0.010, 0.008, and the difference was statistically significant between the two groups. 75 cases of diabetic patients with MRI examination of the pancreas, 1 case were eventually diagnosed as pancreatic cancer Conclusion: The DWI signal of pancreas in diabetic patients gradually decreased with the extension of the course. Some functional changes of the pancreatic cells. Screening early patients with pancreatic cancer whose manifestation was just as diabetic.