Abstract: DC Reference Voltage and leakage current testing are routine test items for metal oxide arresters（MOA）.Accurate measurement of DC reference voltage and leakage current of MOA is the basis of MOA safe and stable operation.In view of the inconsistency between the DC reference voltage and the inflection point voltage of the arrester during the leakage current test without removing the primary lead wire of the 220 kV MOA,this paper puts forward the method of increasing the test voltage of the upper section of the arrester by the resistance partial voltage method and the test voltage of the lower section of the arrester by the voltage rise method, analyzes the influence of the test line angle on the test results, reduces the interference by coating the insulating layer outside the flange, and verifies the feasibility of the method in the field test process.