Abstract: In the cyanidation gold extraction process from gold concentrates, the thickener serves as core equipment for concentrating and washing, with its operational stability and washing performance directly impacting the production efficiency of enterprises. To address the issues of low efficiency, insufficient processing capacity, and poor washing indices in the original thickening-washing system for cyanidation leaching slurry of low-sulfur gold concentrates, Shandong Gold Smelting Company implemented a high-efficiency upgrading and renovation of the ϕ50-meter conventional thickener. While retaining the original tank body, the peripheral drive was converted to a central drive; the rake frame structure and drive system were optimized, and systematic optimization was conducted on the selection, dosing point, and dosage of flocculants to enhance the flocculation and sedimentation performance of the slurry. After the renovation, the underflow sand concentration increased from 30 % to over 55 %; the thickness of the clarified layer rose from 300–500 mm to more than 1 000 mm, and the turbidity of overflow water decreased from 150 NTU to 70 NTU, which significantly improved the washing effect and the quality of the pregnant solution. Practice has demonstrated that this technical route is economically viable; it not only enhances the continuity and stability of system operation but also strengthens environmental compliance capabilities, providing a replicable technical paradigm for the upgrading and renovation of aged thickeners in similar enterprises.