MZ interferometer is used to monitor the processing of the dynamic corrosion process. The

corrosion rate of metal bars can be evaluated with ultra-sensitivity even when the

concentration of NaCl solution is only 0.05 wt%. It is found that the sensitivity response is a

function of the effective refractive index ( RI) . The experimental results reveal that the

speeds of the wavelength shift is up to -9.32×10-² nm / s，and the increase of the peak intensity

is about -3.93×10-² dB / s. Mo- reover，the electrochemical technology is used to accelerate the

corrosion process. And the whole process could be monitored within 1 min. This experiment can

be used as the extension experiment or innovative experiment of the

metal linear expansion coefficient experiment.