A production method, containing the step of: mixing 0.02 to 0.6 parts by mass of an organic peroxide, 0.2 to 300 parts by mass of an inorganic filler, 2 to 15.0 parts by mass of a silane coupling agent, and a silanol condensation catalyst, based on 100 parts by mass of a polyolefin-based resin, in which the inorganic filler has an X value specified by Formula (I) satisfies 5 to 1050, X=ΣA/B  Formula (I) wherein, ΣA denotes a total amount of a product of a BET specific surface area (m2/g) of the inorganic filler and a blending amount of the inorganic filler, and B denotes a blending amount of the silane coupling agent; and a crosslinkable resin composition and a crosslinked resin molded body produced by the production method; and a silane master batch and a molded article.