Abstract: With the gradually mature of the emulsified explosive production technique,the development of emulsified explosive production equipment technique and the improvement of the requirements our county and industry to the safety of emulsified explosive production,it is necessary to ensure the safety of emulsified explosive production by improving the automation degree of emulsified explosive production and reducing the number of online operators.Taking Anhui Hengyuan Technical Research Chemical Co.,Ltd. as an example,the network automatic control system with primary and secondary stations of emulsified explosive production line of the company is designed and developed.In the system,medium-sized Siemens S7-300 PLC system is adopted,a primary station and two secondary stations are set,the communications of the stations is realized by Ethernet,so the transmission bandwidth and efficiency of the control data obtained by the system are improved effectively,the control data of the production process can be processed timely,the rapid output response of system is guaranteed,besides that,the safety of emulsified explosive production is ensured;several upper machines are installed in the system,which is help for operating the system simultaneity,if a single system break down,other standby stations can be assessed to the system.The applications of the system show that since December in 2016,the system is developed and applied,the indexes of some relative standards are met by the emulsified explosive produced by the system,the system operation is table,it can provide some reference for realizing the goals of no (little) humanized operation,intelligent control,diversified platform display,remote operation of production equipment of emulsified explosive production line.

Key words: Emulsified explosive production line, Siemens S7-300 PLC system, Ethernet, Automation control system