Abstract: A solid state relay is provided herein, which utilizes an electromagnetic coupling device for galvanic isolation and providing feedback from the output side to the system side. The solid state relay contains a system-side driving circuit, an electromagnetic coupling device, and an output-side control circuit. The electromagnetic coupling device contains at least a system-side electromagnetic coupling element, a first output-side electromagnetic coupling element, and a second output-side electromagnetic coupling element. The system-side driving circuit is connected to the system-side electromagnetic coupling element, and takes the ON/OFF digital control signals from a digital system as input to turn on and off its driving to the system-side electromagnetic coupling element.