Abstract: With the continuous development of PLC technology,various functions have been fully integrated,and its application advantages in electrical systems gradually become apparent.As an important component of gold mine exploitation,the automation level of the drainage system directly affects the quality of gold mining.The paper in detal introduced the the major characteristics of PLC technology and its advantages.In view of the slow speed and low automation level of the drainage system in a gold mine,study on the automatic control of drainage system is carried out based on PLC technology,and the structural composition,network structure and field application of the system is introduced.With the application of PLC technology to the gold mine,the equipment of the drainage system operates more reliably and stably,improving the automation level of mining operations.