ECE imaging(electron cyclotron emission imaging)is an important diagnostic which can give 2D imaging of temperature fluctuation in the core of tokamak.A method based on ECE imaging is introduced which can give the information of the position of magnetic axis and the structure of internal magnetic surface for EAST tokamak.The EFIT equilibrium reconstruction is not reliable due to the absence of important core diagnostic at the initial phase for EAST,so the information given by ECE imaging could help to improve the accuracy of EFIT equilibrium reconstruction.
