Based on four sectional width of wide slab continuous casting mold of certain steelmaking plant in China, a water model with 1:1 ratio has been established, and according with the orthogonal test method, we study the influence of the different factors on the flow in the mold , the factors includes hole numbers of SEN, the argon gas injection of nozzle, immersion depth of nozzle, casting speed and sectional size of mold. In result, the optimum of operating conditions for four wide slabs continuous casting mold have been obtained.