Denavit-Hartenberg (D-H) is the traditional parametric method for kinematic analysis of parallel robot in research. The positive kinematic analysis is carried out on the robot according to exponential product formula based on the screw theory which taking a 4-R (SS)^2 parallel robot as research object to get the position and orientation transformation matrix. The screw theory was just needed to establish a inertial and a tool coordinate system ( Marked as S and T), and via transformation between each joint variable to get the kinematic eq...