Method for preparing multilayer polyolefine microporous film by wet method

The invention relates to a method for preparing a multilayer polyolefine microporous film by a wet method, which aims at solving the problems of complicated technology and large consumption of extraction agents. The method comprises the following steps: using polyolefine resin as raw material; matching and adding grafting monomers, initiators, solvents and the like into the raw material; and obtaining products of the polyolefine microporous film through a polyolefine solution preparation work procedure, a gel sheet formation work procedure, a stretching work procedure, a filming agent removalwork procedure, a drying work procedure and a heat treatment molding work procedure. The invention has a simple technology, and is applicable to the manufacture of the polyolefine microporous film with more than three layers. The manufactured polyolefine microporous film is applicable to the manufacture of battery diaphragms, capacitor diaphragms, various separation films and the like.