Objective By observing the therapeutic effect of Jiawei Huanglian Wendan Decoction on bile reflux gastritis with symptoms of bitterness in the mouth, it can provide reference for clinical application. Methods According to symptoms, gastroscopy and TCM syndrome diagnosis, 60 patients who met the inclusion criteria were divided into the observation group and the control group with 30 cases in each group by random number table method. The observation group was treated with Jiawei Huanglian Wendan Decoction, while the control group was treated with Hydrotalcite treatment, the course of treatment for 4 weeks. Before and after treatment, the individual symptom scores, TCM syndrome scores, gastroscopy scores and the degree of bile reflux in the two groups were used as indexes for efficacy evaluation and clinical observation. Results Bitter mouth and related symptoms, endoscopic manifestations, and bile reflux degree of patients in both groups were significantly improved compared with those before treatment, and the observation group was better than the control group in terms of improvement of symptoms of mouth pain and reduction of TCM syndrome scores and gastroscopic scores (P<0.05), the total clinical effective rate of the observation group was 90.00%, and the total clinical effective rate of the control group was 70.00%, and the difference between the two groups was statistically significant (P<0.05). Conclusion On the basis of syndrome differentiation, the application of Jiawei Huanglian Wendan Decoction in the treatment of bile reflux gastritis with symptoms of bitterness in the mouth can significantly relieve the symptoms of bitterness in the mouth and the degree of bile reflux, reduce the TCM syndrome score and gastroscope score, and has a significant clinical effect.