By the computer simulation, the cutting course and the mechanics performance of medium-coal-rock roadheader are mastered, which offers the reliable foundation for studying and improving the machine; practical examples are provided for the analysis of the characteristics of cutting header＇s loads and the working performance of the roadheader.

The normal working conditions of the cutters of hard rock TBMs is described,the mechanical factors of the cutters are defined,mechanical analysis and failure analysis are made for the cutters and countermeasures are recommended to control the mechanical conditions of the cutters so as to avoid premature failure of the cutters.