To explore the effect of Zhenggu powder combined with functional exercise in the treatment of knee osteoarthritis and its effect on knee joint function. Methods:All 90 cases of patients with knee osteoarthritis in our hospital from October 2014 to April 2016 were elected and divided into a treatment group （n=45） and a control group （n=45）. The treatment group was treated with Zhenggu powder combined with function exercise treatment, the control group Zhenggu powder, and both treated for 30 d. The clinical efficacy of 2 groups were compared. The knee function of 2 groups before and after treatment was compared using Lysholm knee score. The isometric muscle strength, muscle volume, range of motion, JOA and VAS score of 2 groups before and after treatment were compared.Results:Except the limp, the Lysholm scores of 2 groups increased significantly after treatment （P<0.05 or P<0.01）, and the treatment group was higher than the control group significantly （P<0.05 or P<0.01）; the proportion of normal knee function of the treatment group was significantly higher than that of the control group, the proportion of poor knee function lower （P<0.05）. Compared with those before treatment, flexor muscle strength, scope of activities of 2 groups after the treatment were increased significantly （P<0.05 or P<0.01）, and the treatment group was higher than the control group significantly （P<0.05）; the extensor muscle strength of the treatment group also increased significantly （P<0.05）, but there was no significant difference between 2 groups （P>0.05）. After treatment, subjective symptoms, clinical signs, limitation of daily activities and JOA score of 2 groups were significantly increased, VAS score significantly reduced, and there was significant difference between 2 groups （P<0.05 or P<0.01）. The total effective rate of treatment group was 93.33%, which was higher than 77.78% of control group significantly （P<0.05）.Conclusion:Zhenggu powder combined with functional exercise in treatment of patients with knee osteoarthritis can significantly improve clinical symptoms, reduce joint pain, increase isometric muscle strength and improve the knee joint function and therapeutic effect, and the clinical curative effect is better than applying Zhenggu powder alone.