Abstract: This paper has simulated the driving force of solidification crack of stainless steels, namely the,stress-strain field in the trail of molten-weld pool. Firstly, the effect of the deformation in the molten-weld pool was eliminated after the element rebirth method was adopted. Secondly, the influence of solidification shrinkage was considered by increasing thermal expansion coefficients of the steels at elevated temperature. Finally, the stress-strain distributions of different conditions have been got and analyzed. Furthermore, the driving force curves of the solidification crack of the steels have been obtained by converting strain-position curves into strain-temperature ones which found a basis for predicting welding solidification crack.