In order to improve the low thermal efficiency of Solar Energy Fission Geyser, a VV modulation control system of circulating pump based on fuzzy control has been designed. In this system, SCM P89LPC930 is the core. A digital temperature sensor of 1-wire bus LTM8871 is used to detect the real-time temperature and an inner comparator of P89LPC930 to detect the zero point. According to fuzzy control rules, a best angle is chosen. This technology is applied to drive the AC motor to get constant temperature differential. The system is effective in improving the thermal efficiency and poor circulation by avoiding frequent start-up of circulation pump. The innovation points lie in the system uses a minimum hardware circuit design and fuzzy control, with easy circuit, reliable performance characteristics, thus having a high application value.