The mono-objective flexible job shop scheduling problem (FJSP) is analysed. By making one production as research object, considering parallel machine，waiting time and processing order when manufacturing, with the goal of minimized make span, mathematical formulations and modeling were proposed. The decision-making method of processing order was proposed. A new algorithm was designed based on Dijkstra algorithm. The experiments prove the correctness and effectiveness of this algorithm, and the experience and comparison with other references prove the advantages of this algorithm.