The invention belongs to the technical field of polymer powder processing, and in particular relates to a preparation method of polyether ketone ketone fine powder for coating. The preparation method comprises the following steps: mechanically pulverizing a polymerized polyether ketone ketone polymer, washing and drying to obtain polyether ketone ketone coarse powder, performing stabilizing treatment on the coarse powder, then adding a certain amount of modifier to obtain mixed powder, and pulverizing the mixed powder with air flow to obtain polyether ketone ketone fine powder. The preparation method has a simple process, high pulverization efficiency and low impurity content, the prepared polyether ketone ketone fine powder has uniformity of dispersion and concentrated particle size distribution, the granular form is near-spherical, and the polyether ketone ketone fine powder is particularly suitable for an electrostatic spraying process, and can effectively improve the uniformity and liquidity of coating, decrease coating defects, play the characteristics of the polyether ketone ketone and improve the stability of coating.