The invention relates to a cotton padding, which comprises a cotton padding core, gauze screens and non-woven fabrics. Both upper surface and lower surface of the cotton padding core are provided with a layer of gauze screen and a layer of non-woven fabric in turn; the peripheries of the non-woven fabrics arranged on the upper surface and the lower surface are integrally quilted along the peripheral boundaries of the cotton padding core; the cotton padding core consists of the following components: cotton, hollow fibers, low-melting-point fibers and natural bamboo fibers; and the hollow fibers are at least one of far infrared hollow polyester short fibers, antibacterial polyester hollow fibers, bamboo carbon hollow polyester fibers, three-dimensional crimped hollow fibers and seven-hole polyester fibers. A preparation method comprises the following steps of: mixing, opening, combing, processing by using a random roller, paving, compacting, processing at a constant temperature, shaping, laying a net, rubbing, and reshaping. The components are reasonably proportioned, the processing technology is simple, and the prepared cotton padding has the characteristics of no caking, bacteria resistance and inhibition, health care, moisture absorption and air permeability, and is soft and fluffy and suitable for industrial production.