Disclosed is an overvoltage collecting device based on a zinc oxide varistor. The input end of a zinc oxide arrester Z1 is connected to a circuit to be detected, the output end of the zinc oxide arrester Z1 is connected to the input end of a second zinc oxide varistor valve plate Z3, and the output end of the second zinc oxide varistor valve plate Z3 is connected to the ground. The input end of an isolation sampling circuit is connected to the input end of the second zinc oxide varistor valve plate Z3. The overvoltage collecting device based on the zinc oxide varistor further comprises an overvoltage protection circuit, a first zinc oxide varistor valve plate Z2 and a discharge counting circuit. According to the overvoltage collecting device based on the zinc oxide varistor, the zinc oxide varistor valve plates are arranged below a primary side lightning arrester, after voltage signals are collected from the zinc oxide varistor valve plates, the actual overvoltage of the circuit to be detected is calculated according to the volt-ampere characteristic curve of the zinc oxide varistor, the voltage distribution relation of the valve plates and a certain operational amplifier proportion, the anti-interference signal capacity is high in field measurement, the power frequency overvoltage, switching overvoltage and lightning overvoltage signals of the circuit to be detected can be collected accurately, and the signals with the frequency being 40 MHz can be collected to the highest degree.