The disclosure provides a polymer composite membrane, a method for preparing same, and a lithium-ion battery including same. The polymer composite membrane includes a polymer base membrane, where the polymer base membrane includes a first surface and a second surface disposed opposite to each other, and the polymer composite membrane further includes a first ceramic layer, a first heat-resistant fiber layer, and a first bonding layer disposed sequentially from inside out on the first surface of the polymer base membrane, where materials of the first heat-resistant fiber layer contain a first polymeric material and a second polymeric material.