The invention relates to linseed oil microcapsules capable of quickly forming films to timely repair scratches and a preparation method thereof. According to the microcapsules, linseed oil is used as capsule cores, gelatin is used as a wall material, the capsules are spherical, the average capsule diameter is 20 microns, the capsule walls are uniform, and the surfaces of the microcapsules are smooth. The preparation method comprises the steps of preparing gelatin emulsion and linseed oil emulsion respectively, dripping the linseed oil emulsion into the gelatin emulsion while stirring, and emulsifying the two phases together; adding glacial acetic acid to adjust the pH value of the solution to 4.8, adding an aqueous solution of anhydrous sodium sulfate, and cooling to 20 DEG C to wrap the capsule walls compactly; dripping formaldehyde while stirring, curing capsule films to obtain a solution, and performing freeze drying on the solution to obtain white linseed oil microcapsule solid powder. The gelatin and the linseed oil are emulsified respectively and then emulsified together, so that the linseed oil microcapsules are good in shape, easy in capsule diameter control and stable in solvents such as water, dimethyl benzene and the like; after the microcapsules are added into a coating, the light scattering is weak, and the appearance of the coating is not affected; the linseed oil flowing out after the microcapsules are broken can quickly form the films in oxygen to timely repair the scratches.