A surface wetting treatment method for battery cell diaphragm of new energy automobile battery includes preparing diaphragm, extracting diaphragm, preparing a coating agent, drying the diaphragm, coating the diaphragm, preparing a polyester fiber membrane, unifying two membranes, and performing immersion treatment and vacuum plating. The present invention is characterized in that a diaphragm is made of a mixed material of polypropylene and polyethylene, compared with polypropylene, the diaphragm resists high temperature; compared with polyethylene, the diaphragm resists low temperature; combined with the composite of polyester fiber membrane, the diaphragm has thermal stability, high temperature resistance, low temperature output, long charging cycle life, moderate mechanical strength; andthrough the effect of the extracting agent, the invention facilitates the extraction of the soluble substance after the film is formed, makes the diaphragm into a microporous structure, and cooperates with the stretching action before and after the extraction to make the micropores more uniform, so that the permeability is stronger even when the electrolyte ions are transmitted, and the tensile strength and the mechanical properties of the diaphragm are improved by stretching, so that the diaphragm is not easy to be broken.