Solar energy exists everywhere, which is inexhaustible,pollutless, safe and reliable. When compared with other conventional energy sources,it  has broad prospects for development. The new usage of solar energy for street lamp instead of tradtional way helps to save energy,which also has the following inconparable advantages: clean, sufficient,high level of security, extensive resources, long-life and maintenance-free. Photovoltaic energy is considered to be the most important resource in 21th centry. In recent years, government of all levels have taken steps to promote solar energy, and have created a aggreable environment for its developemnt.