The new FeCrBSiNb-based amorphous coating with low oxide content was prepared by automatic twin wires arc spray process.The oxidation behavior during coating deposition was characterized in detail by following ways.Primary droplets in-flight prior to deposition was collected and characterized by X-ray diffraction.Auger spectroscopy was used to examine the distribution of oxides within individual splat.The scanning clection microscopy equipped with energy dispersive X-ray analysis was also employed to study oxide distribution within coating and exposed surface of a splat.The experimental results indicate that this Fe-based amorphous coating has a very low oxide content of 2 at%,which is very different from the conventional arc spraying Fe-based coating with oxide content of more than 20%.The thick coating formation mechanism of low oxide content coating was discussed based on the thermodynamic and kinetic analysis of as-sprayed coating.The results show that some boron element addition can remarkably decrease oxide content during coating deposition.Boron element can preferentially form boron oxide.Boron oxide exists in outside surface of in-flight droplets and has excellent volatility at high temperature,which prevents the oxidation of alloy during deposition.Hence,the coating has low oxide content and presents excellent mechanical and anti-wear properties.