Provided is a micro-porous polyolefin composite film, the micro-porous polyolefin composite film including a porous coating layer containing a polymer binder and inorganic particles, the polymer binder simultaneously employing an aqueous polymer and a non-aqueous polymer. The contents of the aqueous polymer and the non-aqueous polymer are controlled, and thus optimize heat resistance, adhesive strength, and the moisture content to thereby improve high-temperature stability, and, further, improve the adhesive strength to thereby improve stability in production, and minimize the moisture content to thereby improve reliability of a battery.