Abstract: In order to study the effect of geomagnetic induction current（GIC） generated by geomagnetic storms on excitation characteristics of transformer,taking magnetic wave data measured by Mengcheng observatory in China Anhui area and the earth soil resistivity parameter in the south of Anhui area as the foundation,the area communication network frame model is established.The distribution of earth magnetic field and magnetic induction current during geomagnetic storms（GIC） is obtained based on the calculation of plane wave method.The analysis of GIC on the transformer excitation characteristics of analyzed area is conducted by UMEC transformer model.The joint simulation of geomagnetic field,power system infrastructure and GIC intrusion transformer is realized by using CDEGS,and GIC calculations and risk assessments during geomagnetic storms are further determined.The results show that,under the influence of strong solar storms,geomagnetic storms have a strong impact on the AC power grid in the analyzed area,GIC induced in the grid is much more influential than the DC power transmission,and the peak value of transformer excitation current increases.The proposed method can provide reference for GIC calculation in power system and its influence on the magnetic bias characteristics of transformer.