With the continuous reform of economic system of our country, the computer technology, automatic control technology obtained the rapid development of electronic technology, and promoted the development of the frequency conversion control technology. Frequency conversion control technology for its convenient, efficient and safe characteristics were more and more applied to various fields of people's life, obtained the recognized and widely used in a wide range of industries. Coal mining as a process of huge energy consumption, power consumption, occupied a large proportion in the whole energy consumption, while in the process, there was a lot of energy waste. The variable frequency control technology was introduced in the coal industry and had very important significance for the whole industry, played an important role in energy saving.