This paper introduces a set of electrical energy-saving system for commercial office buildings, aiming at making better use of solar energy and photovoltaic power generation. Solar energy is a renewable energy source, which is inexhaustible clean energy and has great commercial application value. Based on this fact, we plan to design a unique and novel solar shutter in combination with the daily observation and the shape of solar panels. The shutter blades are equipped with an automatic light tracking system, and the angle of the blades can be adjusted in time through photoresistor induction, that is, as much solar energy as possible can be converted into electric energy for load use, and at the same time, comfortable light can be provided for the house. In essence, the system is a small photovoltaic power generation system, which runs all day with high-efficiency based on automatic sun tracking. Among them, the basic operation route includes:solar position detection, computer data processing, photovoltaic and electric volt energy conversion, circuit connection, etc. From the current debugging results, the shutter has the characteristics of humanization, high efficiency, cleanliness and so on. Through this energy-saving system, we hope to maximize the use of solar energy in the premise of low cost, so as to achieve the purpose of energy saving.