Novel organic-inorganic composite conversion liquids were designed and prepared, aiming to address troubles related with the yellowing and inadequate corrosion resistance of the silane film for galvanized fasteners. First, KH-550 (3-amino propyl triethoxy silane) and KH-560 (3-(2,3-epoxy propoxyoxy) propyl trimethoxy silane) were mixed and hydrolyzed to get organic component, and two series liquid silicates K₂SiO₃ and Na₂SiO₃ were prepared by reaction of KOH and NaOH with SiO₂ of varying proportion to get silicates of different modulus respectively as inorganic component. Next the novel composite organic-inorganic conversion liquids were obtained by compounding the organic component with the two series inorganic components at 9:1-1:9 respectively. Further, galvanized fasteners were immersed in the liquids for 30-60 s, subsequent dried, and cured at 80-120 ^oC for 10 min and followed at 180-200 ^oC for 30 min, thereby, an organic-inorganic conversion film is formed on the galvanized fasteners. The storage stability of the conversion solution and the yellowing resistance of the conversion film were evaluated by macroscopic observation. Results of neutral salt spray testing and copper sulfate titration testing reveal that the corrosion resistance of the potassium silicate containing conversion films was superior to the sodium silicate containing conversion films. The corrosion resistance of conversion films with varying proportion of organic component was assessed by the forementioned way (note, by taking M1(9:1) as an example, herewith M1 presents modulus 1 and 9:1 presents the ratio of the two components). Besides, the corrosion resistance of conversion films prepared with conversion liquids composed of varying proportion of organic component to potassium silicate series of different modulus was assessed by the forementioned way. Meanwhile, the morphology, composition, mechanical properties and corrosion resistance of the conversion film, which presents the best corrosion resistance were characterized by means of scanning electron microscopy, energy spectroscopy, pencil hardness tester, and polarization curve test. The results showed that the prepared films M₁(9:1), M₁(8:2), M₁(7:3), M₁(1:9), M₂(9:1), M₂(8:2) and M₃(9:1) all showed a clear and transparent state, without delamination or gel, showing good storage stability. After 72 h salt spray test, the surface of the M₃(9:1) conversion film remained intact and clean, without any white rust or red rust, showing the best corrosion resistance. The film is transparent, eliminating the yellowing phenomenon of traditional silane films. SEM observation showed that the film was compact and uniform, tightly bound to the matrix, and had excellent physical shielding performance. The results of the pencil hardness test and adhesion test further confirm that the film has good mechanical properties.