The research background and significance for the computer monitoring and control system of the pumped storage power plant is introduced in this paper. The key techniques that are adopted in the development of the local control unit（LCU） in the domestic computer monitoring and control system are explained. Based on the domestic computer monitoring and control system of Shisanling Pumped Storage Power Plant， the control strategies for the parallel running between the new and the old systems， the database interface， the communication scheme， the system structure and configuration are discussed.