The invention provides an arrester ground lead monitoring and early warning device and an arrester ground lead monitoring and early warning method. The arrester ground lead monitoring and early warning device comprises an outer shell, a central processing unit, an equipment monitoring unit, an alarm device and the like. The arrester ground lead monitoring and early warning method comprises the steps of detecting the resistance of a ground lead by use of a resistance detector, recording occurrence times of thunder currents in the ground lead by use of a pulse inductor, and the like. The arrester ground lead monitoring and early warning device and the arrester ground lead monitoring and early warning method can be used for performing real-time monitoring and early warning on the ground lead of a lightning conductor, conveniently and reliably, solving the operation and maintenance problems of the arrester ground lead, improving the safety, and avoiding equipment damage or pedestrian safety hidden danger during thunderstroke caused by undiscovered ground lead damage; meanwhile, the arrester ground lead monitoring and early warning device and the arrester ground lead monitoring and early warning method can be used for recording and accounting the thunderstroke frequency, ensuring that personnel can inspect lines with frequent thunderstrokes conveniently and prevent hidden dangers. The arrester ground lead monitoring and early warning method can be used for performing effective and comprehensive monitoring and early warning, and avoiding careless omission, and has a relatively good accounting effect.