The invention discloses a set adjustable output online analysis method based on coal quality fluctuation state identification. The method comprises steps that 1), for all the multiple coal pulverizers in operation, the real-time operation monitoring data of each coal pulverizer and of the set of the coal pulverizers is acquired; 2), according to constraint conditions, overmeasure of each coal pulverizer is calculated; 3), the overmeasure of all the coal pulverizers is gathered to acquire an increasable set coal feeding quantity; and 4), an adjustable overmeasure scope of a set power generation load can be calculated in combination with the present operation data and present coal types. The method is advantaged in that the coal pulverizer overmeasure and the adjustable output of the set can be timely broadcast based on the real-time operation monitoring data of the coal pulverizers, the electric power scheduling operation personnel is facilitated to timely master set power generation capability change conditions, and electric power scheduling load control strategies are optimized.