Abstract: Objective: We intend to evaluate the application value of optimal monochromatic spectral CT imaging performed on patients with gastric variceal bleeding before endoscopic treatment by way of observing the manifestation of portal vein, gastric varies gastro renal shunt etc. Methods: A total of 60 patients with gastric variceal bleeding admitted to our hospital from September 2016 to January 2021 were selected for spectral CT portal venography. By comparing the CT value of hepatic portal vein, the image noise (IN), the signal-to-noise ratio (SNR), contrast noise ratio (CNR) and subjective evaluation of the image quality among the 3 sets of images of optimal monochromatic energy group, 70keV group and mixed energy group (QC), we obtained the spectral CT portal venography with the best image quality for the imaging diagnosis. Results: The average CT values of hepatic portal vein of the 3 groups (the optimal monochromatic energy group, 70keV group and QC group) vein were 273.12±25.48, 168.70±20.16 and 164.92±20.74, respectively. the average IN value were 31.22±4.13, 17.72±3.09 and 24.25±2.98, respectively. The SNR were 8.95±1.80, 9.92±2.64 and 6.93±1.37, respectively. The CNR were 6.18±1.52, 4.82±1.71 and 3.22±0.99, respectively. While the subjective evaluation scores of image quality were 4.57±0.63, 3.10±0.98 and 2.47±0.93, respectively. All showed significant statistical difference except the average CT value of hepatic portal vein between the 70keV group and QC group. The CT portal venography with optimal monochromatic energy was the best, and it showed clear manifestation of gastric renal shunt, gastric varices, portal vein thrombosis, etc. Conclusion: The optimal monochromatic spectral CT imaging can optimize the image quality and it shows high application value when treated patients with gastric variceal bleeding before endoscopic surgery.