The invention discloses a paint protective coating and a preparation method thereof. The paint protective coating is composed of the following components by mass: 10-30% of organic fluorine-silicon resin; 66-89% of n-butanol; 0.5-4% of perfluoropolyether; and 0.05-0.15% of a curing agent. The preparation method consists of: dissolving organic fluorine-silicon resin in a n-butanol solution in proportion, then adding perfluoropolyether and the curing agent, stirring the substances evenly at 20DEG C-30DEG C, and performing curing, thus obtaining the paint protective coating. The paint protective coating provided by the invention can cure into a film at room temperature curing, has the characteristics of high hardness, long service life and easy cleaning, and has hydrophobic and oleophobic self-cleaning function.