Abstract: Aim To research the interpolation algorithm of parallel connected machine tool based on stewart mechanism.Methods\ The common idea of time discrete interpolation algorithm and the inverse kinematics model of parallel connected machine tool were used to evaluate the relation between tool motion path and six telescopic legs and to derive one kind of interpolation algorithm.Object oriented program design method was adopted to work out the simulation software and the availability of the interpolation algorithm was testified by computer simulation.Results and Conclusion\ Simulation results of machining process of sphere parts and one sheet hyperboloid parts show that the interpolation algorithm proposed is correct and practical, providing a new and feasible interpolation algorithm for parallel connected machine tool.