Objective To evaluate the therapeutic effect of Du meridian moxibustion on ankylosing spondylitis (AS) of kidney yang deficiency type. Method Sixty patients with active AS of kidney yang deficiency type were randomly allocated to treatment and control groups, 30 cases each. The treatment group received Du meridian moxibustion plus oral administration of sulfasalazine tablets and the control group, sham moxibustion plus oral administration of sulfasalazine tablets. Treatment was given once every other day, four weeks as a course, for a total of two courses. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score, the Pain Visual Analogue Scale (VAS) score, the Bath Ankylosing Spondylitis Functional Index (BASFI) score and the Bath Ankylosing Spondilitis Metrology Index (BASMI) score were recorded and laboratory safety indicators were observed in the patients. Result The TCM syndrome score decreased in both treatment and control groups of AS patients at four and eight weeks of treatment (P<0.05). The therapeutic effect was significantly better in the treatment group than in the control group (P<0.05). There was no statistically significant difference in therapeutic effect between different courses (P>0.05). The BASDAI, VAS, BASFI and BASMI scores decreased in the two groups of AS patients at four weeks of treatment (P<0.05). They decreased more in the treatment group at eight weeks of treatment; there were statistically significant differences compared with the control group (P<0.05). The laboratory safety indicators were not markedly abnormal. Conclusion Du meridian moxibustion can effectively relieve the clinical symptoms and does not cause obvious adverse reactions in AS patients. It is a safe and effective way to treat AS.