An electrostatic discharge (ESD) circuit is used to protect an internal circuit. The ESD circuit includes: an ESD clamp, having a first terminal connected to a power and a second terminal connected to a ground voltage; and a first switch, connected between an ESD terminal of the ESD clamp and the internal circuit. A gate of the first switch is controlled by a state signal in the ESD clamp to turn off the first switch when an ESD event occurs on the first terminal of the ESD clamp and turn on the first switch when the ESD event does not occur.