本文介绍了一种基于单片机的太阳能控制器，系统使用低功耗、高性能的AT89S51单片机作为控制电路的核心器件。此系统由太阳能电池模块，蓄电池，充放电电路，电压采集电路，单片机控制电路和光耦驱动电路组成。设计使用PWM（脉宽调制）控制技术来控制蓄电池充放电，通过控制MOSFET管开启和关闭达到控制电池充放电的目的。实验结果表明，该控制器性能可靠，可以监视太阳能电池和蓄电池电池状态，实现控制蓄电池最优充放电，达到延长蓄电池的使用寿命。-This paper introduces a solar controller based on MCU, AT89S51 chip with low power consumption, high performance of the system as the core device control circuit. This system consists of solar battery module, battery, charging and discharging circuit, voltage acquisition circuit, SCM control circuit and optocoupler drive circuit. Design using PWM (pulse width modulation) control technology to control the battery charge and discharge, by controlling the MOSFET tube open and closed to control the battery charge and discharge of the objective. The experimental results show that, the controller performance is reliable, can monitor the solar cell and battery state of charge and discharge the battery, to achieve optimal control, to prolong the service life of the battery.