Abstract: This paper introduces a supervision and control system for wind-photovoltaic-battery power plants,with a detailed interpretation of related key techniques and main functions of the system.It also illustrates the data acquisition and demonstration program,automatic generation control（AGC） program,and automatic voltage control（AVC） program for wind-photovoltaic-battery power plants.The technological functions have been realized in a national demonstration project of wind-photovoltaic-battery power plant.