Abstract：Objective：To observe the clinical efficacy and safety of modified Dabuyuan Decoction as an adjuvant for metastatic castration-resistant prostate cancer （mCRPC） of qi and blood deficiency type. Methods： A total of 110 mCRPC patients of qi and blood deficiency type treated at Zhejiang Dinghai Hospital from September 2020 to September 2024 were selected and randomly divided into a control group and a Dabuyuan Decoction combination group using the random number table medthod， with 55 cases in each group． The control group received conventional treatment according to the mCRPC diagnosis and treatment consensus． The Dabuyuan Decoction combination group received modified Dabuyuan Decoction in addition to the control group's treatment regimen．Both groups were treated for 21 days per cycle，for a total of 6 cycles．The study follow-up lasted until 10 months after the end of treatment， with a total observation window of 14.5 months．Solid tumor and bone metastasis status，traditional Chinese medicine syndrome scores （including pale or sallow complexion，fatigue and lack of strength，shortness of breath and reluctance to speak， dizziness and blurred vision， pale lips and nails）， serum prostate-specific antigen （PSA） levels， traditional Chinese medicine clinical efficacy， and adverse reactions were observed and compared between the two groups． Results： After 6 cycles of treatment， the scores for individual symptoms and the total traditional Chinese medicine syndrome score in the Dabuyuan Decoction combination group were lower than those in the control group，with significant differences （P＜0.05）．After 6 cycles of treatment，serum total PSA （tPSA） and free PSA （fPSA） levels in both groups decreased compared to before treatment，and the Dabuyuan Decoction combination group had lower tPSA and fPSA levels than the control group，with significant differences （P＜0.05）．After 6 cycles of treatment，the total effective rate for solid tumor efficacy was 56.36% （31/55） in the Dabuyuan Decoction combination group and 36.36% （20/55） in the control group，with significant difference between the two groups （P＜0.05）．The traditional Chinese medicine clinical efficacy rate was 76.36% （42/55） in the Dabuyuan Decoction combination group and 56.36% （31/55） in the control group，with significant difference between the two groups （P＜0.05）．There were no significant differences in the incidence of adverse reactions，bleeding-related adverse events，or coagulation function between the two groups （P＞0.05）． Conclusion： Modified Dabuyuan Decoction as an adjuvant demonstrates good clinical efficacy in mCRPC patients of qi and blood deficiency type， reduces tumor marker levels， and lowers the incidence of adverse reactions.