The invention discloses a preparation method of an ablation-resistant composite material wind cover. The preparation method comprises the following steps of preparing of a high temperature-resistant sand coating, preparing of a wind cover model and coating, box loading, metal smelting and casting, cooling, post-treatment and the like. The preparation method has the beneficial effects that the silica sand material with larger granularity is coated to the surface of the wind cover model at the outer surface of the wind cover, liquid steel can permeate into a gap between sands, and a metal and sand mechanically mixed ablation outer casing is formed; by adopting the technology of controlling the casting temperature of the liquid steel and the vacuum degree in a sand box, the thickness and uniformity of the mixed sintering ceramic layer are controllable, the ceramic layer is firmly adhered with the steel of the main body, the melting point is high, the hardness is high, the ablation-resistant property is strong, and the functions of delaying the ablation of the wind cover and prolonging the service life are realized; the procedures are simple, the number of auxiliary tools is fewer, thehigh temperature-resistant sand is free from sticking and can be repeatedly used, the production efficiency is high, and the cost is low.