The invention relates to a method for preparing a SiOC ceramic coating through CO2 laser cracking of a polysiloxane material. According to the method, firstly, a mixed solution of the polysiloxane material is prepared, and a coating A is prepared on the surface of a Fe-based metal with a brush-coating or spray-coating method; under protection of inert gas, the coating A is scanned by the aid of continuous high-energy controlled laser to react, and the SiOC ceramic coating is prepared. The ceramic coating is prepared through laser cracking of the polysiloxane material with the method, the preparation period is short, the ceramic surface is smooth, the porosity is low, and the prepared ceramic coating has good anti-corrosion and wear-resistant characteristics. A new method is provided for solving the problem that reliable service of pure Fe-based metal materials under some harsh working conditions is difficult to realize.