Abstract: Through the analysis of working mechanism and technological process of foam molding machines，adopting PLC and touch screen technology to foam molding machines in a factory for bulk modification，designs the electrical control system of a foam molding machine based on Mitsubishi FX_2N series PLC. With a touch screen interface, the action time for each process can be input，the mode of operation can be selected，and the process parameters can be displayed. The control system improves the production efficiency and production quality of foam products.

Key words: Mitsubishi FX_2N series PLC, foam molding machine, electrical control system