Abstract: 19-filament MgB2 superconductor wire had been successfully prepared via restacking with mono filament Cu/Fe wire and drawing process. Inner flaw of the single-core wire could be measured by eddy current testing system. The intersection SEM results showed that compared to the better one, the wire with inner flaw will be liable to result into poor quality of 19-filament MgB2 superconductor wire, for example, worse distributed core, fragile Fe layer inside the wire, which will depress the superconducting properties much. So, the quality of 19-filament Fe/Cu MgB2 superconductor wire can be better controlled aided by eddy current inspection technology.