Objective To investigate the clinical efficacy of heat-sensitive point thunder-fire moxibustion in treating knee osteoarthritis (KOA). Methods One hundred and forty-eight KOA patients were randomly allocated to treatment and control groups, 74 cases each. The treatment group received heat-sensitive point thunder-fire moxibustion and the control group took diclofenac sodium enteric-coated tablets. The Visual Analogue Scale (VAS) score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and 50 yards fastest walking time were observed in the two groups before and after 30 days of treatment. The clinical therapeutic effects were compared between the two groups. Results There were statistically significant pre-/post-treatment differences in the VAS score and WOMAC subscores in the two groups (P<0.01). There was a statistically significant pre-/post-treatment difference in 50 yards fastest walking time in the treatment group (P<0.05). There were statistically significant post-treatment differences in the VAS score, the WOMAC score and the WOMAC pain and stiffness scores between the treatment and control groups (P<0.01). There were statistically significant differences in the VAS and WOMAC scores at three months after treatment between the treatment and control groups (P<0.01). The total efficacy rate was 95.9%at the end of treatment and 95.6%at three months after treatment in the treatment group, and 86.1%at the end of treatment and 86.8%at three months after treatment in the control group; there were statistically significant differences between the two groups (P<0.05). Conclusion Heat-sensitive point thunder-fire moxibustion is an effective way to treat knee osteoarthritis.