Abstract: Aiming at the switching overvoltage of 35 kV AC reactors and the aging problem of traditional resistance-capacitance (RC) protection devices, this paper proposes a new type of nonlinear RC protection scheme. The core of the scheme is to replace the fixed resistor of the traditional RC device with a zinc oxide varistor and adapt it to the metal oxide surge arrester, so as to realize the isolation of the device under normal operating conditions and dynamic connection when overvoltage occurs. Field tests show that the device can effectively suppress the voltage oscillation when the reactor is disconnected, solves the aging defect of traditional devices, provides a feasible technical solution for 35 kV reactor overvoltage protection, and has certain engineering application value.