The invention discloses a tape-casting preparation method of an alumina silicate porous ceramic material with a three-dimensional net structure. The preparation method comprises the following steps: adding alumina silicate polycrystalline fibre,alumina silicate ceramic fine powder, a binder, a plasticizer and a dispersant into water, uniformly mixing, and defoaming by vacuum mixing to obtain stable slurry; moulding the prepared slurry on a tape-casting machine to obtain alumina silicate polycrystalline fibre membrane green-body; laminating the membrane green-body, drying, dumping, and sintering so as to obtain a porous ceramic material which is formed by mutual connection of crystal grain and fibre and has a three-dimensional net structure. The material has a net structure formed by mutual connection of crystal and fibre, and has high porosity and filtration flux and excellent mechanical strength.