The invention discloses a method for oxidizing and removing sulfide from Bayer-process crude liquid. The method comprises the following steps of introducing strong oxidizing gases such as ozone into the Bayer-process crude liquid, and oxidizing low-valence sulfur and other reducing substances in the crude liquid; carrying out oxidation reaction in a crude liquid conveying pipe or a reaction kettleor other closed containers; adding a small amount of lime milk into the reacted crude liquid, and conducting uniform mixing; carrying out conventional Bayer-process crude liquid filtration refining on the mixed crude liquid to remove solid suspended matter. According to the method, the sulfur-containing impurities in the crude liquid can be effectively removed under the conventional temperature condition of the Bayer-process crude liquid, and the impurity content of Bayer-process alumina products can meet the standard.