The invention discloses a coal-fired set largest power generation load data processing method based on coal moisture. The method comprises steps that lab test analysis on incoming coal moisture of a coal pulverizer is carried out; a largest output of the coal pulverizer under reference moisture and ventilation resistance of the coal pulverizer under the largest output are queried; a largest grinding output of the coal pulverizer is determined according to the largest output under the coal moisture and the reference moisture of the coal pulverizer; a largest drying output of the coal pulverizer is determined according to inlet-outlet pressure difference of the coal pulverizer and the ventilation resistance of the coal pulverizer under the largest output; the smaller one of the largest grinding output of the coal pulverizer and the largest drying out of the coal pulverizer is selected as the largest output of the coal pulverizer; all the largest outputs of the coal pulverizer are gathered; a largest power generation load of the set is determined according to set equivalent load coal feeding amount and all the largest outputs of the coal pulverizer. Through the method, timely forecast of the largest output of the coal pulverizer and an adjustable set output can be realized, electric power scheduling operation staff are facilitated to timely master power generation capability change situations of sets in a whole province, and thereby safe, economical and high-quality power grid operation is guaranteed.