Abstract: This paper introduced the research of rotary balance test support interference in FL-8 low speed wind tunnel,including the test method,equipment and results.To realize the function of support and angle variation,an angle variation rod was designed.Test results showed that the support interference of the longitudinal and lateral aerodynamic forces was different,the influence of support interference was irrelative to the rotational direction in the longitudinal results,and it was opposite with different rotational direction in the lateral results.The results after support interference correction of dorsal and rear sting support were close to each other,which indicated that the correction was reasonable,and the accuracy of the test results was improved.