Abstract: Variable axes NC machine tools enjoy many advantages over their conventional counterparts. These advantages include high rigidity and accuracy, desirable force/weight ratio and readiness in the implementation of modularization. Nonlinear coupling in Stewart platform makes the design and testing of this kind of machine tools very complicated and must be implemented with the computer. For the variable axis NC machine tool model BKX I modeling of the sample machine and kinematic simulation have been performed on an environment of Visual C++ and Open GL. The softwares provided reliable foundations for the successful design and test run of the machine tool.