For problems of long starting and stopping time and large power consumption existed in current starting and stopping technology for coal flow system of coal preparation plant, an optimization scheme of starting and stopping technology for coal flow system of coal preparation plant was proposed. Equipments of coal flow system powered by the same transformer are taken as starting unit. Equipments in the same starting unit start simultaneously or start in batches in set sequence according to load factor of the transformer, and different starting units start simultaneously. No-coal time node of each equipment of coal flow system is measured manually, and equipment stopping time node delays 3-5 seconds behind the no-coal time node, so as to realize each equipment stopping wihout coal immediately according to direction of coal flow. The actual application results show that starting time reduces 57.9% and stopping time reduces 35.2% by use of the optimization scheme, which achieves good energy-saving effect.