Objective: To evaluate the efficacy and safety of Tongxuekang capsule in the treatment of knee osteoarthritis. Methods: Single-centred, open self-control methods before and after administration were performed in different time length of 14 days, 28 days, 56 days and 84 days to observe for improvement by evaluating knee joint pain scores, WOMAC scores, and doctors and patients' scores on the overall condition of the disease before and after treatment. Results: A total of 34 patients with primary knee osteoarthritis from October 2016 to September 2017 were enrolled in Xijing Hospital. There were 7 males and 27 females with an average age of 54 years and an average body mass index of 25 kg/m2. Joint pain scores, WOMAC scores, and doctors' and patients' overall scores for the disease were significantly improved compared to prior treatment, with no significant adverse reactions in all patients. Conclusion: Tongxuekang capsule is safe and effective in the treatment of knee osteoarthritis and thus, can be used as a treatment option. In order to conduct further studies on the effectiveness and safety of consumption with the use of the capsule in a larger population, an increase in the sample size of the current study is necessary.