Abstract： Objective： To observe the clinical effect of modified Xiexin Daochi Powder combined with western medicine on recurrent oral ulcer （ROU） of accumulated heat in heart and spleen type. Methods：A total of 82 patients with ROU of accumulated heat in heart and spleen type admitted to Yuhuan Haicheng Oral Outpatient Department from June 2020 to April 2023 were divided into the control group and the observation group by the random number table method，with 41 cases in each group. The control group was given conventional western medicine treatment，and the observation group was treated with modified Xiexin Daochi Powder on basis of the conventional treatment. Both groups were treated continuously for two weeks. The traditional Chinese medicine （TCM） syndrome scores，Visual Analogue Scale（ VAS） scores，ulcer diameters，immune function indicators，and levels of serum tumor necrosis factor（ TNF）-α and interleukin （IL）-6 were compared before and after treatment in the two groups；the clinical efficacy and disease recurrence were evaluated. Results：After treatment，the total effective rate in the observation group was higher than that in the control group（ P＜0.05）. After treatment，TCM syndrome scores，VAS scores，ulcer diameters，and levels of CD8+，TNF-α and IL-6 in the two groups were decreased when compared with those before treatment，and the levels of CD3+ and CD4+ were increased （P＜0.05）；TCM syndrome score，VAS score，ulcer diameter，and the levels of CD8+，TNF-α and IL-6 in the observation group were lower than those in the control group，and the levels of CD3+ and CD4+ were higher （P＜0.05）. The recurrence rate in the observation group was 4.76%（1/21）， lower than that of 42.86%（6/14） in the control group （P＜0.05）. Conclusion：The combination of modified Xiexin Daochi Powder and western medicine has a definite effect on ROU of accumulated heat in heart and spleen type，which can alleviate pain， improve immune function，and reduce the inflammatory responses and disease recurrence rate.