The invention discloses a manufacturing method for an iron-based nanocrystalline inductance core. The manufacturing method orderly comprises steps of winding, thermal processing, solidifying, cutting, surface pre-processing, protection processing and corrosion processing as well as cleaning. In the corrosion processing step, corrosion process is conducted to a cutting surface of a magnetic core blank body achieved via the protection processing step with a corrosion solution; and solute of the corrosion solution can be one or more of ferric trichloride, ferric nitrate, copper nitrate and cupric chloride. The method improving magnetic core inductance has simple technology process, and is easy to operate; batch production can be achieved; and labor intensity can be effectively reduced and production efficiency can be improved.