In order to solve the problems of arc whistling during arc welding after the arc striking of the inverter welding machine,the anti-biasing ability of the nanocrystalline magnetic core is analyzed,acomparative test is designed,and a new nanocrystalline strip composition is deployed to replace the original 1K107B material,and the transformer core made of the new composition strip has lower remanence and loss,and the anti-biasing ability of the nanocrystalline core is improved. The test results show that the transformer wound with this magnetic core will not enter the saturation zone when the magnetic bias continues to increase,which avoids deep saturation of the transformer and inverter failure,enhances the transformer’s ability to resist magnetic bias,greatly improvesthe reliability of the inverter welding machine and eliminates the arc whistling.