manipulation. First of all， aiming at the most important eddy current detection of

non-destructive detection， the uniqueness of the

solution for the inverse problem is proved， according to the theory of electromagnetic radiation.

Secondly， the theory of eddy detection in industry and some factors that influence eddy

detection are investigated. Lastly， because the Maxwell’ s equations are equivalent

between arbitrary curved coordinate systems and rectangular coordinate systems， by

changing the permeability and the dielectric constant， the coordinate of electromagnetic

field can be changed accordingly， which results in controlling the eddy current field.