Flexible anti-cracking film coating and preparation method thereof

The invention relates to the technical field of coatings, and particularly discloses a flexible anti-cracking film coating which comprises a component A and a component B, the mass ratio of the component A to the component B is (2-4): 1; the component A is prepared from the following components in parts by mass: 50 to 120 parts of polyether triol, 10 to 30 parts of polyether glycol, 10 to 20 parts of 4, 4 '-diamino-3, 3'-dichlorodiphenylmethane, 1 to 5 parts of triethylene diamine, 1 to 2 parts of dimethyl siloxane, 5 to 10 parts of N-hydroxysuccinimide, 1 to 2 parts of calcium carbonate, 1 to 5 parts of liquid coumarone resin, 10 to 20 parts of plasticizer, 1 to 2 parts of antioxidant, 1 to 2 parts of defoaming agent, 1 to 2 parts of light stabilizer and 5 to 10 parts of porous protein; the component B is prepared from the following components in parts by mass: 20 to 40 parts of polyether triol, 10 to 20 parts of benzoic acid polyol ester plasticizer, 20 to 40 parts of diphenylmethane diisocyanate, 2 to 4 pa