The basic principles of multi-layer correlation method are analyzed.An experimental platform for testing the lift-off effect of planar eddy current array sensor is established

and the noised output signals of eddy current array sensor are denoised using multi-layer correlation method

which is followed by extracting of amplitude ratio and phase difference information between the output signal and pumping input signal.Besides the influences of lift-off on output characteristics are also considered.The result shows that multi-layer correlation method is applicable in denosing of the output signal of eddy current array sensor

and the signal-to-noise ratio（SNR）is substantially improved.As the lift-off distance increases

the amplitude ratios between the output signal and pumping input signal are monotonically increased

while the phase differences remain unchanged.These rules provide a reference for further research and application of the sensor.