Breaking over-voltage is one of the main reasons for the burnout of the dry-type air-core shunt reac-tor. In order to achieve an effective protection for this over-voltage，the combined protection method which consistsof an arrester and a RC absorbing device is presented in this paper. Both mathematical analyses on circuit theoriesand simulation analyses on preventive effect by the ATP-EMTP software are carried out. Research results indicatethat，the arrester which has the different frequency response characteristic is lack of effective protection for the arcreignition over-voltage. The RC absorbing device is fit for the protection of the breaking over-voltage，but a largercapacitance and a higher power resistance are needed in the high chopping current condition. The combined protection device partially suppresses the over-voltage amplitude and decreases the oscillation frequency by the RC circuit，which will reduce the frequency response demand of the arrester. It actively suppresses the high chopping cur-rent over-voltage by the arrester

which will reduce the capacitancedemand. The combined device is more applica-ble to the protection of breaking over-voltage for the reactor

and ithas an application prospect.