The invention relates to a double-component single coating chrome plating plastic part colored paint and a preparation method thereof. The paint comprises, by weight, 2-20 % of pigment powders, 1-5 % of padding, 1-5 % of extinction powders, 20-35 % of hydroxy acrylic resins, 15-25 % of thermoplastic acrylic resins, 0-3 % of expoxy resins, 1-3 % of dispersing agents, 0.5-3 % of adhesion promoters, 15-25 % of solvents and 8-10 % of curing agents. The preparation method includes sequentially adding the hydroxy acrylic resins, the dispersing agents and 30-50wt.% of solvents into a burdening kettle, stirring, slowly adding the pigment powders, performing high-speed dispersing, then grinding by a sand mill to obtain a first slurry, adding the thermoplastic acrylic resins into the burdening kettle, stirring, sequentially adding the first slurry, the expoxy resins, the adhesion promoters, the padding, the extinction powders and 10-20wt.% of solvents, and performing the high-speed stirring to obtain a second slurry, adding the curing agents and residual solvents into the second slurry, and fully stirring to obtain the paint. Compared with paints in prior art, the paint has an excellent adhesive force on the chrome plating plastic parts and excellent water resisting property and weather resistance.