The Internet of Things lightning arrester online monitoring device, the intelligent online monitoring IED and the state monitoring integrated server together form the Internet of Things lightning arrester online monitoring system. The lightning arrester monitoring adopts a wireless remote transmission monitor to realize a fully isolated sampling method without residual voltage. The lightning arrester is used to obtain energy and power supply. The collected current is converted into a voltage signal and then entered into the wireless sending module, and the measurement result is transmitted wirelessly The data acquisition device IED, the device will receive the voltage signal through the wireless receiving module, and then enter the signal conditioning circuit, and use a unique expert diagnosis system to scientifically analyze and diagnose the collected data, and then analyze whether the state of the arrester is normal and faulty species. Timely and conveniently understand and grasp the health status of substation equipment. Through real-time monitoring of the lightning arrester's leakage current and the number of lightning strikes, the monitored data is analyzed, fitted and processed, and combined with the on-site working conditions, the leakage current of the porcelain sleeve or the leakage current of the insulating rod caused by the pollution or internal moisture of the arrester can be found in time Increase and other issues to avoid accidents.