The invention discloses a method for preventing sagger corrosion during the cathode material lithium cobaltate sintering process, and belongs to the field of lithium ion battery manufacture. The materials after the first sintering and second sintering in the production process of lithium cobaltate are grinded and graded, and during the grinding and grading process, the fine particles are collected by a cloth bag deduster. Before the first sintering of lithium cobaltate, the fine particles are evenly paved on the sagger to form a layer with a thickness of 5 to 15 millimeters, then raw materials that are needed for the first sintering are filled in the sagger, and then pressed by a steel plate, and finally the sagger with raw materials is placed in a furnace to carry out sintering. The method can effectively prevent sagger corrosion, protects the fireproof material on the surface layer of the sagger, prevents lithium cobaltate product from being adhered on the fireproof material, and prolongs the service life of sagger. In the provided method, the lithium cobaltate product will not contain the fireproof materials (Al or Mg compounds) on the surface layer of the sagger, the purity of the lithium cobaltate product is increased, and thus the quality of the lithium cobaltate product is improved.