The　material　quality　of　metallic　cylinders　including　microstructure　is　reflected　in　their　physical　properties.　Eddy　current　testing　techniques　play　an　important　role　in　the　measurement　of　metallic　cylinder　measurement.　In　this　paper,　a　cylinder　radius　and　permeability　estimation　method　is　proposed　based　on　the　combined　analytical　and　optimisation　method.　The　Dodd　and　Deeds　analytical　model　has　been　first　simplified,　which　suggests　an　approximate　linear　relationship　between　the　cylinder　radius,　permeability　and　coil　inductance.　Based　on　the　proposed　relation,　the　pre-estimated　radius　and　permeability　are　used　as　the　initial　guess　for　the　modified　Newton-Raphson　algorithm　to　solve　the　least　squares　problem　between　the　measured　and　calculated　coil　inductance　spectra.　This　method　avoids　the　local　minimum　issue　that　occurs　otherwise,　to　some　extent.　The　effectiveness　of　the　proposed　method　has　been　evaluated　by　numerical　simulations　and　experiments,　which　indicates　that　fast　estimation　can　be　achieved　with　high　accuracy.