Preparation method of water-based fiber leather base cloth with sandwich rainbow structure

The invention provides a preparation method of water-based fiber leather base cloth with a sandwich rainbow structure, which comprises the following steps: preparing sandwich non-woven fabric by a needling composite process, and sizing the thickness and gram weight of the sandwich non-woven fabric; the sandwich non-woven fabric sequentially comprises an upper unfixed island sea-island fiber layer, a polyester mesh layer and a lower unfixed island sea-island fiber layer from top to bottom. The required water-based fiber leather base cloth with the sandwich rainbow structure is obtained through the processes of dipping the sandwich non-woven fabric in water-based polyurethane slurry, solidifying and drying, reducing with methylbenzene, oiling, rubbing, buffing and dyeing and finishing with acid dye liquor in sequence. The prepared water-based fiber leather base cloth with the sandwich rainbow structure is bright in cross section color, full in layering sense and capable of meeting market requirements; and the m