Objective: This study aims to establish an acute gastric mucosal injury (AGMI) rat model induced by different concentrations of hydrochloric acid (HCl) and investigate the effects of intravenous injection of different concentrations and doses of Evans Blue (EB) on the survival rate and surface exudation of the model. Methods: Study 1: Wistar rats were randomly divided into five groups based on body weight: 150-180g group, 180-200g group, 200-250g group, 300-400g group, and 400-500g group, with a total of 40 rats in 8 subgroups based on HCl concentration (0.40M, 0.45M, 0.50M, 0.55M, 0.60M, 0.65M, 0.70M) and a control group treated with physiological saline, with 3 rats in each group and a total of 120 rats. The survival rate of rats in each group was evaluated after modeling for 24 hours, and the interaction between body weight and HCl concentration on rat survival was analyzed. On the basis of determining the five gradient HCl concentrations, the pathological changes of gastric mucosa were observed under microscopy using hematoxylin-eosin staining. Study 2: The highest concentration of HCl was selected for model preparation, and AGMI rats were randomly divided into six groups based on different concentrations and doses of EB: 0.5% (0.4ml) group, 1% (0.1ml/100g) group, 1% (0.2ml/100g) group, 2% (0.1ml/100g) group, 2% (0.2ml/100g) group, and 5% (0.1ml) group, with 5 rats in each group and a total of 30 rats. The survival rate (24 hours after injection) and degree of surface exudation of rats in each group were evaluated. Results: Study 1: The symptoms of AGMI rats after modeling were positively correlated with HCl concentration, and the 24-hour survival rates of rats in the 0.65M and 0.70M groups were both 0% across all body weight groups. The Kaplan-Meier survival curves of rats of different body weights showed significant differences in survival rates among rats treated with different concentrations of HCl (P<0.00). The interaction analysis showed a significant interaction between HCl concentration and body weight in terms of observed survival time (P<0.00). The histopathological observation of gastric mucosa in rats treated with the determined five gradient HCl concentrations (0.40M, 0.45M, 0.40M, 0.45M, 0.50M, 0.55M, and 0.60M) showed that the gastric mucosal tissue of rats in the physiological saline group had intact structure without inflammatory cell infiltration. The degree of inflammatory cell infiltration in AGMI rats was positively correlated with HCl concentration. Study 2: In AGMI rats prepared with 0.60M HCl, the survival rate after intravenous injection of 5% EB (0.1ml) was only 40% at 24 hours. The Kaplan-Meier survival curves showed no statistically significant difference in survival rates among AGMI rats treated with different concentrations and doses of Evans Blue (EB) (P>0.05). The results of surface exudation in AGMI rats after intravenous injection of EB showed that rats in the 0.5% (0.4ml) group did not have any color change in the skin and eyes, and had fewer surface exudation points, or even no exudation points. Rats in the other groups had more obvious exudation points. Among them, rats in the 2% (0.1ml/100g) and 2% (0.2ml/100g) groups had better skin color and exudation conditions. The skin color of rats in the 2% (0.2ml/100g) group further deepened over time at 24 hours after EB injection (28 hours after modeling). The results of surface exudation in AGMI rats after intravenous injection of EB showed that rats in the 0.5% (0.4ml) group did not have any color change in the skin and eyes, and had fewer surface exudation points, or even no exudation points. Rats in the other groups had more obvious exudation points. Among them, rats in the 2% group had better skin color and exudation conditions. The surface exudation at 24 hours after EB injection further showed that the skin color of rats in the 2% (0.2ml/100g) group deepened over time. Conclusion: Modeling with HCl can achieve the establishment of multiple precise concentration gradients. Fasting rats with a body weight of 180-200g can be administered HCl at concentrations of 0.40M, 0.45M, 0.50M, 0.55M, and 0.60M to prepare the AGMI model. Intravenous injection of 2% EB (0.2ml/100g) will be conducive to the study and analysis of the distribution characteristics of surface exudation points in AGMI rats over time and with changes in the condition.