Aim To explore the effect of cuminaldehyde in cumin fruit on gastric ulcer and the protective mechanism via establishing the gastric ulcer model of rats was by ethanol injury. Methods Thirty-six male R. norregicus were divided into six groups: control group, model group, omeprazole positive control group and cuminaldehyde low, medium and high dosage groups. After seven days of continuous intragastric administration, the acute gastric ulcer of R. norregicus was tested by absolute alcohol. Gastric ulcer area, inhibition rate, gastric tissue antioxidant activity, serum inflammatory factors and gastric mucosal protective factors were detected in different groups. Results The results showed that cuminaldehyde significantly reduced the area of gastric ulcer and increased the inhibition rate of gastric ulcer. The inhibition rate of cuminaldehyde at high dose group was up to 74.65%, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH) in gastric tissue significantly increased, and the contents of serum prolandin E