Objective To study the clinical efficacy of Qihuang-Juantong decoction combined with morphine sulfate sustained-release tablets in treatment of cancer pain. Methods A total of 107 patients with cancer pain were divided into the control group (n=53) and the treatment group (n=54) randomly. The control group were treated with morphine sulfate sustained-release tablets, and the treatment group were treated with Qihuang-Juantong decoction combined with morphine sulfate sustained-release tablets. The two groups were treated for 14 days. The clinical efficacy of the two groups after treatment was compared. The kamofsky performance status (KPS) score of the two groups before and after treatment were compared. The initial dose and dose after two periods of treatment of morphine sulfate sustained-release tablets of the two groups were compared. The CD4+, CD8+ and CD4+/CD8+of the two groups before and after treatment were compared. The adverse reactions rates of the two groups during the treatment were compared. Results Total effective rate of treatment group was 92.59％ (50/54), which was significantly higher than the control group 71.70％ (38/53), and the difference was statistically significant (χ2=7.996, P<0.05). After treatment, the KPS score (70.3 ± 6.4 vs. 63.4 ± 6.0, t=5.711) in the treatment group were significantly higher than that in the control group (P<0.05), the dose after two periods of treatment of morphine sulfate sustained-release tablets (42.20 ± 5.31 mg vs. 47.08 ± 6.23 mg, t=4.364) in the treatment group were significantly lower than that in the control group (P<0.01). After treatment, the CD4+(45.58％ ± 6.17％ vs. 31.06％ ± 4.87％, t=13.496), CD4+/CD8+(1.26 ± 0.15 vs. 0.69 ± 0.10, t=23.083) in the treatment group were significantly higher than those in the control group (P<0.05), the CD8+(36.18％ ± 3.36％ vs. 44.96％ ± 5.04％, t=10.621) in the treatment group were significantly lower than those in the control group (P<0.01). The adverse reactions rate of the treatment group during the treatment was 11.11％ (6/54), which was significantly lower than the control group 35.85％ (19/53), and the difference was statistically significant (χ2=9.142, P<0.05). Conclusions The Qihuang-Juantong decoction combined with morphine sulfate sustained-release tabletshas a good efficacy and low adverse reaction rates for the cancer pain, can improve the quality of life and cellular immune function, reduce the dose of opioid, and it was worthy clinical application.