In recent years, hybrid devices have increasingly received more research.However, few of researchers studied the dynamic analysis. The inverse dynamic analysis of a novelhybrid machine tool designed in Tsinghua University is presented. The hybrid machine tool underconsideration consists of parallel and serial structures, which is based on a new 2-DOF parallelplatform and serial orientations. The kinematics and the dynamic equations are studied first for theparallel structure through Newton-Euler approach. And then, the dynamic analysis for serialstructures is conducted. Finally, a closed-form inverse dynamic formulation is derived by using someelimination techniques. Some simulation results are also given.