A control system capable of controlling activating/deactivating of multiple motherboards via cloud includes a plurality of motherboards, a plurality of power supplies respectively corresponding to the motherboards, a cloud monitoring platform, and a power on/off control module connected to the motherboards and signally electrically connected to the cloud monitoring platform. The cloud monitoring platform includes a graphic control interface, and allows to a user to log in for operations to generate a control signal. After receiving the control signal, the power on/off control module analyzes the control signal to determine to output a trigger signal to at least one of the motherboards. In response to the trigger signal received, the motherboard outputs a power on/off signal to the corresponding power supply connected to turn on or turn of that power supply.