The relationship between the frictional work and wearing volume of disc cutters is analyzed on the basis of the macro energy conversion of disc cutter wearing, and the disc cutter wearing prediction model based on the macro energy theory is established. Furthermore, the relationship between the micro wearing particle furrow of the disc cutter and the macro wearing loss is analyzed on the basis of the micro wearing mechanism of disc cutters, and the disc cutter wearing prediction model based on micro wear mechanism is established. The two prediction models are verified through field test data acquired in the construction of a water conveyance tunnel. Conclusions drawn are as follows: 1) These two prediction models can provide reference for the prediction of the disc cutter wearing; 2) It is necessary to establish the selection criteria for the key parameters by means of experiments, so as to improve the prediction accuracy.