The invention relates to a detergent and washing resistant, waterproof and moisture-permeable bi-component film and a preparation method thereof. The preparation method comprises the steps of mixing, blank formation, pushing, degreasing treatment, drawing longitudinally, drawing in a two-way arc-shaped manner, sintering solidification after drawing transversely, and laminating by adopting a release paper transfer method. The bi-component film prepared by the steps is applied to the fields such as functional garments, special equipment clothes, down garments, recreational sports garments, shoemaking and the like, wherein a polytetrafluoroethylene microporous film has the thickness of 20-50 microns and porosity of more than 80%, and the bi-component film has the thickness of 50-80 microns, has the light weight, has functions of keeping out the wind, perspiring, water proofness, moisture permeability, ultraviolet ray resistance, corrosion resistance, warming and the like, and is suitable for diversified products made of functional materials in the fields of sports, leisure, women and children.