Abstract: By experiments based on uniform design, the influenc of many coating ingredients on the weld fume quantity and emission rate were studied.9 coating ingredients were taken as independent variables and were divided into 6 levels in all 24 experiments. The weld fume quantity and emission rate were taken down when welding and the data were put into the computer to process statistically.The analysis results give the mathematic model and diagrams between independent variables and functions.The results indicate that the effects of many coating ingredients on the weld fume quantity and emission rate were in the mutual form.All the mutual effects between BaF₂ &CaF₂, and titania powder &BaCO₃, rutile & CaF₂, and aluminium magnesium powder &iron powder increase the weld fume quantity.While the mutual effect between titania &rutile decrease the weld fume quantity.The effects of coating ingredients on the weld fume emission rate are similar with that on the weld fume quantity.