The invention provides a biaxially-stretched breathable film and a production method thereof, and relates to the technical field of polymeric materials. The biaxially-stretched breathable film is produced from polyethylene, ultrafine calcium carbonate powder, an antibacterial master batch, a rheological agent and a dispersant. The method adopts a biaxial stretching technology characterized by carrying out film blowing and transverse stretching firstly and then carrying out longitudinal stretching, so the method has the advantages of simple molding technology, high film forming rate, low cost,wide processing range of the polyethylene resin, conveniently controlled processing conditions, good film forming ability of the resin, and easiness in processing film-formation, and the breathable film produced through matching the raw materials has high strength and good breathability.