Workflow technique is a research hotspot in the field of advanced manufacturing technology. However, up to now workflow simulation still lacks necessary evaluation of rationality and validity. Therefore, a principle of workflow simulation was set forth; a kind of workflow simulation mechanism is proposed. It is divided into presentation layer, business logic layer and database layer. Then, taking process of handling business orders as example, and taking time, quality, cost and service as key factors, a feasible method was developed. Its simulation results of 30 days were listed and analyzed. At last, an amended process of handling business orders is brought forward.