To explore the curative effect and adverse actions of ultrasonic conductance transmission technology combined with external treatment of Zhentong Formula in treating yin syndrome of cancer pain. Methods: The patients with cancer pain (n=120) were randomly divided into two groups. Patients in treatment group received ultrasonic conductance transmission technology combined with external treatment of Zhentong Formula, while the control group gave patients ultrasonic conductance transmission technology combined with external treatment of placebo for 7 days. The analgesic effect, initial time, and adverse actions of the treatment were observed in both groups. Results: The total effective rate of relieving cancer pain of treatment group was 86.7%, and that of control group was 33.3%, which showed significant difference (P<0.05). NRS scores of treatment group before and after treatment were significantly different (P<0.05), but there was no significant difference of NRS scores in control group before and after treatment. The effective time of treatment group started on day two on average with mild side effects and good dependence. Conclusion: Ultrasonic conductance transmission technology combined with external treatment of Zhen Tong Formula has a good curative effect on treating a variety of cancer pain with quick effect and slight adverse actions.