The invention belongs to the field of film-wrapped stranded conductors, and particularly provides a low-
dielectric-loss paint film composition and a preparation method thereof and a film-wrapped stranded conductor. The preparation method of the low-
dielectric-loss paint film composition comprises the following steps that S01,
ferrocenecarboxylic acid, octaaniline propyl cage-shaped polysilsesquioxane and
diethylene glycol are taken and mixed, N, N-
dimethylformamide is used for dispersion, and a mixture is obtained; stirring and reacting at
room temperature to obtain a precursor liquid, then supplementing octaaniline propyl cage-shaped polysilsesquioxane, continuously reacting, then supplementing N, N-
dimethylformamide, re-dispersing, and recording as a liquid A for later use; s02, dihydric
alcohol and diisocyanate are taken and mixed, the mixture is heated for a reaction, then N, N-
dimethylformamide is added for dispersion, and after
continuous treatment, a
polyurethane prepolymer dispersion liquid is obtained and marked as a liquid B for standby application; and S03, mixing the solution A with the solution B, and concentrating to obtain the paint film composition. The paint film composition prepared by the invention has the advantages of low
dielectric loss and good mechanical properties.