The invention relates to a preparation method of novel water-based weather-resistant conversion type antirust paint and belongs to the field of paint preparation. According to the method, a polyphenol type rust converting agent is obtained through reaction of gluconic acid and epoxy monomers, and the paint can be prepared after the polyphenol type rust converting agent and a fluorine-containing acrylic emulsion are compounded, wherein phenolic hydroxyl groups of the homemade polyphenol type rust converting agent can coordinate with iron ions to produce stable ligands, the ligands become a beneficial component in a film and are firmly attached to the surface of steel, a protective sealing layer is formed, the steel is prevented from being oxidized and rusted, double effects of rust removal and rust prevention are realized, the fluorine-containing acrylic emulsion has better heat stability, chemical stability, weather resistance, non-stick property, chemical corrosion resistance as well as water and oil resistance, and the prepared antirust paint can directly cover the metal surface without phosphorization and passivation treatment and has the excellent anti-rust effect.