This paper presents the design model for inverse kinematics Stewart tricept platform as a parallel structure robot which has three fixed prismatic actuators. The portable robot showed fast, consistent and solid structure which recommended to portable Computer Numerically Controlled (CNC) machine that can easily be moved to large parts and perform various operations. The mechanism has 3 degrees of freedom and the 3D model has been built in Solidworks both for design and performance simulation purposes. An exact, Simulation results show that the proposed mechanism is able to perform movements in (X,Y,Z) under pressure In all flexibility, and operation performances Required; analytical geometry method for determining the inverse kinematics solution of a parallel kinematic mobile structure is developed. Machine control elements performance was checked using Simulink and Matlab software. The proposed parallel manipulator shows better orientation capability and is very meaningful to the development of the multi axes hybrid machine tools.