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 equation finally. By comparison with the D-H method, this method made the motion models much more simplified, and meaning of geometry was much more clear. Finally, the parallel robot was kinematically simulated by Matlab to construct its simulation model. Confirmed the parameters of the robot’ s every structure and got some output results by inputing several random joints variables. The accuracy of the method of the screw theory is verified by comparing the output results obtained with the ones calculated.