The present invention relates to a multilayer composite material and preparation method thereof, and it relates to the improvement of the processing technology of a packaging material by using an extrusion lamination equipment in the flexible packaging industry. In particular, the present invention relates to a method for reducing the processing cost of the multilayer composite material with CaCO3. The present invention is an improvement in layering and filling processing, which leads to a cost reduction to manufacture multilayer composite material, reducing of the usage of the organic materials PE, and also meets the environmental protection requirements.
