At present

in the steady state analysis of power system

the control value of unified power flow controller is usually determined by trial method. And the calculation is based on offline typical operating data

which makes it inefficient and less accurate. In order to make up the defect of current analysis

an UPFC control value tuning method based on power transfer distribution factors is brought up in this paper. When N-1 line tripping fault occurs

based on DC power flow method

the control value isset and the N-1 line overload is eliminated by UPFC ’s power control.Furthermore

the control scheme list could be formed and updated based on energy management system（EMS）data. This method mentioned above could provide decision making support to power grid dispatching institutions. The results of a simulation example shows that the method is efficient and utilizable.