The invention relates to a method for reducing slag formation at a superheater part of a coal burning boiler. The temperature of flue gas at the bottom of the superheater is controlled to be less thanor equal to the sum of the melting temperature (DEG C) of coal ash and 100 DEG C. In particular, when the platen superheater is adopted, the control is carried out under the BMCR working condition. Compared with the method for controlling the slag formation at the platen zone by controlling the fume temperature of a hearth outlet, the method for reducing slag formation at platen zone of coal burning boiler is more direct and effective.