The A2 stage of duodenal ulcer is adopted from the ulcer typing method of Dr. Takao Sasaki of Japan. The A2 stage, also known as the active stage, refers to the ulcer surface necrosis, thinning of the covering moss, and obvious congestion and edema in the periphery, which is one of the active stages and a heavier one. Among the digestive system diseases, duodenal ulcer has a high incidence, mainly due to the application of non-steroidal anti-inflammatory drugs, bad eating habits, Helicobacter pylori infection, and psychological factors that lead to the defect of the muscular and mucosal layers of the duodenum. If the treatment is not timely, it will lead to many serious complications, such as perforation and bleeding. Therefore, stage A2 duodenal ulcer indicates a serious condition, which should be taken seriously and should be promptly diagnosed and treated.