The invention discloses a coal dressing method and system of four-product jigging primary cleaning and secondary head coal small simplified heavy medium reelecting. The invention is a coal dressing method and system that selects the secondary head coal product through the four-product jigging technique and then reelects the secondary head coal with small simplify heavy medium separation technology. The adoption of the invention to select coal is characterized by less total investment, simpler system and lower operational expense, which can improve the stability of the system, reduce the powerconsumption, simplify the managing and maintaining work. The method can be easily realized with present technical merits, which is beneficial to be popularized in the middle and small coal washeries where the management level is low and if the method is used in oversize coal washeries, the cost for washing is lower.