A safety control system that can realize comprehensive safety control for a manufacturing site is provided. A safety control system includes an arithmetic operation processing unit, a data storing unit that stores safety input/output data, and a plurality of communication processing units that exchange safety input/output data with a device that is a connection destination. Each of the plurality of communication processing units, independently from processes of the other communication processing units, periodically transmits safety output data for a target device stored in the data storing unit to the target device and writes safety input data from the target device into the data storing unit in accordance with a connection setting set in advance for each of the communication processing units.