Abstract: To solve the problems caused by γ-ray coal ash monitors poor adaptability to raw coal properties variation,variation in short period in coal blending as well as costing much labor power,material resources and time,the method called "inspection every day,comparison every three days" is made to set ash monitors. The application shows that this method improves the device adaptability to raw coal properties variation and solves many problems existing in previous calibration method like requiring much resource,machine downtime with load; and that a lot of workload is reduced like sampling,sample preparation and assay.