The invention discloses a preparation method of a fluorine-containing polymer foaming coating composite filter material. The preparation method is characterized by comprising the following steps: blending PTFE emulsion and perfluoroethylene propylene copolymer emulsion, and then adding an additive to prepare a foaming coating solution; after cutting glass fiber base cloth, flatly laying the glassfiber base cloth on an operating surface of a film coating machine; absorbing the foaming coating solution, dripping the foaming coating solution at one end of the glass fiber base cloth, then scraping the foaming coating solution to the other end of the glass fiber base cloth by using a scraper, so as to enable the foaming coating solution to be uniformly smeared on the surface of the glass fiberbase cloth; taking down the glass fiber base cloth, and sequentially carrying out first-stage drying and second-stage drying; and naturally conducting cooling. The fluorine-containing polymer foamingcoating composite filter material prepared by the preparation method of the invention has the advantages of small air permeability and pore diameter, the foaming coating solution partially permeatesinto the base cloth after foaming coating treatment, larger gaps among longitudinally and transversely interwoven fibers are filled, a microporous film is formed on the surface of the filter material,the interception area is effectively increased, and the filtering precision and the filtering efficiency are improved.