Abstract: For the flow shop scheduling problem which aims to minimize makespan, this paper gives a new derivation about its mathematical definition. A new heuristic method is proposed to shorten the waiting time of each job as much as possible on the basis of reducing the processing time of the first machine and last job. The result of simulation experiments shows that, the new heuristic algorithm has good performance, and the average quality and the stability of scheduling sequences generated by new method are significantly better than other heuristic algorithms with same complexity.