The present disclosure provides an industrial robot safety control system, a back-up safety circuit and a safety module. The safety module includes a first safety circuit and a second safety circuit. The first safety circuit and the second safety circuit receive a warning signal at a same time. The first safety circuit is configured to respond to the warning signal. The second safety circuit include a delay system and an event response circuit. The delay system sets a time delay when receiving the warning signal, wherein, when the delay system does not receive a first control signal indicating that the first safety circuit has responded to the warning signal during the time delay, the delay system controls the event response circuit to respond to the warning signal. The present disclosure may help avoid the problem of common mode failure of the back-up safety mechanism.