To compare the effects of three different polishing methods on the kerf quality, inner wall surface quality and corrosion resistance of biopsy needles by laser cutting, biopsy needles are processed with optimized technological parameters. Biopsy needles are polished separately by electrolytic plasma polishing (EPP), magnetic abrasive finishing (MAF), electro-polishing (EP). The kerf quality is observed with two-dimensional image measuring instrument. The Ra and the surface morphology of the inner wall is measured and observed by the 3D measurement laser microscope. A polarization curve is plotted to verify the corrosion resistances of the biopsy needles with three different polishing treatments. Three methods namely EPP, MAF and EP can be used to completely remove the dross and oxides, reduce the Ra and improve the surface quality. The corrosion resistance of biopsy needle by magnetic abrasive finishing has been significantly improved.