The issue of nondestructive testing in aeronautical structures is of considerable importance in the aviation industry today. And a high sensitivity magnetic field sensor, which has recently been developed is designed for non-destructive stress testing. It is based on idea of the magnetic field produced by pulsed currents and perturbed by the presence of stress. The sensor can be effectively utilized for the detection of defects and stress concentration in conducting materials using eddy current testing measurements. The principle of the measuring technique is based on the unbalance of the magnetic field where the stress or cracks exist. Also, the excited input-signal is special designed. A pulsed current was inputted and changed into a self-attenuation signal which does the effect in the probe.