The invention discloses an electric station powder preparing system regulating method based on furnace entering coal moisture. The method comprises the following steps that an equation set used for calculating the furnace entering coal moisture is built according to a thermal balance formula in an electric station powder preparing system; the furnace entering coal moisture in the electric station powder preparing system is calculated according to the built equation set; and the outlet air powder mixing temperature of the electric station powder preparing system is regulated according to the calculated furnace entering coal moisture. In addition, the invention also discloses an electric station powder preparing system regulating device based on furnace entering coal moisture. The method and the device provided by the invention can be adopted for realizing the real-time on-line calculation on the furnace entering coal moisture, the outlet air powder mixing temperature of the electric station powder preparing system is regulated in real time, a good regulating effect is realized, in addition, sufficient safety is realized, the cost is lower, and the popularization is easy.