In this essay, the experimental material is 5.0 mm thick high strength steel plate, and analyzes the weld shaping, droplets transfer characteristics and melt flow on impurity distribution of hybrid welding processes of CO2 laser-MAG hybrid welding with different the distance between laser and arc. Experimental results show that: the effect of two heat sources interaction effect is changed with different distance with laser and arc. When the distance is 4 mm,the frequency of the droplet transfer is the maximun and the weld shaping is more smooth. The crystallization process of the molten pool accompanied by the liquid metal flow. And the influence of the liquid metal flow is very important to melt flow on impurity distribution. When DLA＝3 mm and the distance to molten pool surface is 1.0 mm the adding elements in the molten pool content is higher and its distribution is the most uniform.