Abstract: In order to ensure the safety of the welded structure of the aluminum alloy fan impeller,the working load was calculated for a certain type of fan impeller,mainly including air resistance and centrifugal force. For single blade,air resistance was only 43. 1 N,however the centrifugal load was 2 433. 6 N,so the main working load was the centrifugal force. The welded structure needed to carry the centrifugal force and welding stress,so it was the weak link of the component. Then the strength analysis was carried out,including theoretical calculation and finite element analysis,which proved that the strength of the welded structure was sufficient. The theoretical calculation was verified by using both the welding industry standard and the fan industry standard. The results showed that the outer pass was more favorable for welded structure to withstand the working load than the inner pass.