In this paper, the flow rule of metal during the deep drawing of the non-symmetry workpieces was investigated by means of the numerical simulation of deep-drawing processes of square cup under bilateral constrained conditions. The numerical simulation was carried out by advanced analysis software Dynaform5.5. SUS304 stainless steel was used as the deforming materials. The influence of different friction coefficient and blank holder force on the drawing forming quality was analyzed. The results showed that the material flow in different areas has different trends with increase of friction coefficient and blank holder force.