The utility model discloses a tertiary two -dimensional code of coal sample is encrypted and is prevented cheating system belongs to thermal power plant management technique field, including administrative center's unit, one -level encryption unit, second grade encryption unit and the tertiary unit of encrypting, utilize the characteristic of two -dimensional code to carry out data encryption, the inspection flow of going into coal after the factory divide into three stages to encrypt in grades, the plain code handing -over of no coal sample in the whole coal sample inspection flow and the substep sets up the code encryption, has avoided inspection process's human factor to disturb completely, has improved fuel checking's standardization, fairness and fairness greatly.