Abstract: By dynamically changing the volt-ampere characteristic, the controllable metal oxide arrester (MOA) can achieve the deep limitation of the switching overvoltage, and thus eliminate the closing resistor of circuit breaker in UHV system and improve the economy and reliability of UHV projects. We investigated the influences of controllable MOA on the amplitude, distribution and waveform characteristics of closing overvoltage, and also investigated the adaptability of parameters of the controllable MOA for different system conditions and line lengths. Moreover, we proposed a parameter configuration of the controllable MOA to eliminate the closing resistor of circuit breaker, analyzed the control strategy and implementation method of controllable MOA, and studied the working conditions of the controlled MOA with different parameters under different operating conditions. The research results show that, by using controllable MOA with controllable ratio of 15% to 25%, the closing overvoltage for UHV lines with length of less than 400 km can be limited within the allowable range. The control of the controllable MOA can be realized by monitoring the line voltage to determine the line status. Under the proposed parameter configuration and control strategy, the energy consumption and the power frequency voltage withstand of the controllable MOA can meet requirements.