In view of the manufacturing problems of multi-batch production and small quantity with each batch in flexible manufacturing system(FMS), the temporal feature and genetic algorithm(GA) in FMS dispatching process across different FMS manufacturing stages were analyzed. Based on the temporal optimization of the FMS manufacture, a time-driven FMS work process was proposed and the workflow dispatch scheme was optimized based on GA. Its performance in FMS workflow scheduling was shown based on a series of conditions such as a double-workstation, continuous operating mode and random initial status.