The invention provides a compound filter pad, and a preparation method and application thereof. The compound filter pad comprises a polypropylene SMS nonwoven fabric surface layer, a water-absorbing fiber layer and a backing adhesive bottom layer, wherein a hot air flow guide layer is arranged between the polypropylene SMS nonwoven fabric surface layer and the water-absorbing fiber layer; the pore diameter of the polypropylene SMS nonwoven fabric surface layer is controlled at 16[mu]m or below; and the hot air flow guide layer is a composite material layer composed of synthetic fibers and cellulose. The preparation method comprises the following steps: performing spunbonding-melt blowing on polypropylene particles, and performing hydrophilic modification by means of an anionic surfactant to obtain the polypropylene SMS nonwoven fabric surface layer; and sequentially superimposing the polypropylene SMS nonwoven fabric surface layer, the hot air flow guide layer, the water-absorbing fiber layer and the backing adhesive bottom layer from top to bottom, and performing extrusion and compounding to obtain the compound filter pad. The compound filter pad provided by the embodiments of the invention is favorably applied to the aspect of a particulate fat purification process; and the formed compound filter pad is high in surface smoothness, causes less fat waste and achieves high oil absorption and water removal effects, thereby being very beneficial to wide popularization and application.