Objective:To evaluate the clinical efficacy of Huaiqi Huang Granules combined with conventional Western medicine therapy for the treatment of Kawasaki disease in children.Methods:A randomized controlled trial study was conducted. A total of 96 children with Kawasaki disease admitted to Hebei Children's Hospital from August 2022 to July 2024 were selected as the research objects and divided into the observation group and the control group by the random number table method, with 48 cases in each group. The control group received conventional Western medicine treatment on the basis of symptomatic treatment, while the observation group took Huaiqi Huang Granules on the basis of the control group. The treatment for both groups lasted 7 d. TCM symptoms scores of both groups were evaluated. ELISA was used to detect the levels of TNF-α, MCP-4, and IL-8, while fluorescence immunoassay was used to detect the levels of von Willebrand factor (vWF), endothelin-1 (ET-1), and nitric oxide (NO); flow cytometry was used to detect CD4 +, CD3 +, CD8 + levels and calculate CD4 +/CD8 +ratio; adverse reactions were recorded during treatment and clinical efficacy was evaluated. Results:The total effective rate was 93.75% (45/48) in the observation group and 77.08% (37/48) in the control group, with statistical significance ( χ2=5.35, P=0.021). After treatment, the scores of persistent high fever, skin macules, red throat and eyes, and fatigue in the observation group were lower than those in the control group ( t values were 5.66, 5.45, 5.03, and 5.42 respectively, P<0.01). After treatment, the levels of serum TNF-α, MCP-4 and IL-8 in the observation group were lower than those in the control group ( t values were 4.10, 5.97 and 3.82 respectively, P<0.01). After treatment, the levels of serum vWF [(19.43±3.85) μg/L vs. (23.02±4.13) μg/L, t=4.41] and ET-1 [(38.54±5.12) μg/L vs. (43.90±5.26) μg/L, t=5.06] in the observation group were lower than those in the control group ( P<0.01); the level of NO [(81.23±8.44) μg/L vs. (74.42±8.13) μg/L, t=4.03] was higher than that of the control group ( P<0.01); after treatment, the levels of serum CD4 + and CD3 + and the ratio of CD4 +/CD8 + in the observation group were higher than those in the control group ( t values were 4.91, 4.23, and 3.81 respectively, P<0.01); the CD8 + level was lower than that of the control group ( t=4.19, P<0.01). During the treatment period, the incidence of adverse reactions was 10.42% (5/48) in the observation group and 8.33% (4/48) in the control group, without statistical significance ( χ2=0.12, P=0.726). Conclusion:Huaiqi Huang Granules combined with conventional Western medicine therapy can effectively reduce the TCM syndrome score of children with Kawasaki disease, inhibit the levels of inflammatory factors, improve vascular endothelial function, enhance the body's immunity, and have good medication safety.