The mechanism and hardware layout of removal device and the design methods of control software were described. The control system which was based on PLC was characterized by simple structure, reliable operation and convenient debugging. A distributed control system was built, adopting the PROFIBUS fieldbus which was used in industrial control applications worldwide. The manmachine interface PC which was designed by using Siemens WinCC system provided an easy to operate and reliable performance intelligent software to the automated control system. Automatic removal device of investment casting explosive mold riser saves a lot of manpower and improves security and automation level of the whole process of removal of riser.