The kinematic mathematical model is established using the DH displacement matrix method in order to achieve accurate kinematic control for the photovoltaic (PV) Panels Cleaning Robot. The mechanisms were also divided into actuator space and joint space as well as pose space according to the properties of variables. Each mapping relationships among the three kinds of space was figured out respectively from the starting of solving for the kinematics and utilizing the geometrical characteristic of the mechanisms. The kinematics model of an excavator working device was built in MATLAB，which validity of the kinematics model was verified. The result provides the theoretical basis for kinematics point trajectory planning and kinematic simulation as well as dynamic analysis of the PV Panels Cleaning Robot.