Objective To explore the best intervention time of peripheral facial paralysis (Bell' s palsy) treated with acupuncture-moxibustion and the clinical superiority of acupuncture-moxibustion by stages. Methods Multi- central large-sample randomized controlled trial was carried out. Nine hundred cases of Bell' s palsy were randomly divided into 5 treatment groups, named as acupuncture by stages group, acupuncture by stages with moxibustion group, acupuncture by stages with electroacupuncture group, acupuncture by stages with line-puncture on muscle region of meridian group and acupuncture without stages group. Four sessions of treatment were required in each group. The clinical curative effects of groups were assessed by House-Brackmann Scale, Facial Disability Index Scale and Degree of Facial Nerve Paralysis Scale during the enrollment, after 4 sessions of treatment, and during 1 and 3 months of follow-up after treatment. The systematic analysis of curative effects was provided in view of the intervention time and nerve localization of disease separately. Results The cure rates of intervention treatment were 50.1% (223/445) in acute stage and 52.1% (162/311) in resting stage, superior to that of 25.9% (35/135) in recovery stage (both P〈0.001). There was no statistically significant differences in comparison of curative effect in 5 solutions at the same stage (all P〉0.05). The effect of treatment intervened at acute stage was superior to that at recovery stage in acupuncture by stages group and acupuncture without stages group (both P〈0.01). There were statistically significant differences in curative effect of the localization above and below chorda tympani nerve in acupuncture by stages with line-puncture on muscle region of meridian group (P〈0.01). The curative effect of the localization below chorda tympani nerve was superior to that above the nerve. Conclusion The best intervention time for Bell' s palsy is at acute stage and resting stage, meaning 1 to 3 weeks after