Symmetrical non-directional eddy current detection sensor and detection method

The invention relates to a symmetrical non-directional eddy current detection sensor, which comprises a symmetrical excitation module and a detection module; the symmetrical excitation module comprises four excitation coils and a symmetrical skeleton, and is used for generating mutually symmetrical plane eddy current fields with equal amplitudes and opposite directions on the surface of a detectedworkpiece. Four identical exciting coils are wound on a symmetrical framework in pairs in opposite winding directions, sinusoidal signals with the same frequency/phase and amplitude are introduced, and plane eddy current fields which are equal in amplitude, opposite in direction and mutually symmetrical are generated on the surface of a detected workpiece, so that output signals of a detection coil in a balanced state are close to zero; the anti-interference capability of the sensor is improved, and the sensor has very high sensitivity to defects in any direction; the orthogonally-arranged main detection coil group a