Abstract: Aimed for the big spatters of CO₂ gas shield welding,the study group carried out a rudiment attempt that control the spatter in CO₂ gas shield welding with longitudinal magnetic field on the base of studying its short-circuiting transfer principle and cause of the spatters.Based on a great deal of experiments,the conclusion was obtained as follows: under certain weld criterion parameter,longitudinal magnetic fields can restrain the spatter of CO₂ arc welding short-circuiting transfer effectively,obtain good technical effect; At the same time,there is an optimal range of magnetic field in which the effect of spatter controlling is best.