【Abstract】 Objective To explore a solution that can inhibit gastrointestinal motility and thus reduce the rate of focal fusion failure in PET/CT images of gastric cancer patients, and analyze its clinical significance from the accuracy of measurement quantitative parameters. Methods The region of interest boundary delineation technology was used as the quality determination method for PET/CT image fusion, and the fusion effect was divided into two categories: good fusion (satisfying diagnostic needs) and bad fusion (failing to meet diagnostic needs). According to the set of conditions for clinical suspicion between 2020.1-2020.5 gastric cancer need PET/CT check the images in 87 patients of decision fusion effect, including 23 patients with poor fusion, the fusion patients with bad stomach refill (tell patients bedside drink 500 mL water more) line after local single beds, PET/CT imaging in the same way again to judge image fusion effect. Moreover, images of patients undergoing initial Uptake were used as control group and images of patients undergoing gastric filling were used as observation group to statistically compare Max Standardized Uptake Value and metabolic tumor volume. Results In the first imaging, 23 of 87 patients had poor image fusion, accounting for 26-44%;Among the 23 patients collected after gastric refill, 1 patient had poor image fusion, accounting for 4-44%.There was no significant difference in MTV40% between the two groups (x2=0.00, P＞0.05). SUVmax in the control group was significantly higher than that in the observation group, the difference was statistically significant (x2=8.33, P＜0.05). Conclusion Compared with the conventional method, the refilling method can significantly reduce the defect rate of lesion image fusion in PET/CT examination of gastric cancer patients, and it is statistically significant to improve the measurement of semi quantitative parameter SUVmax, which has clinical promotion significance.