The study focuses on optimizing flocculation parameters to enhance the thickening efficiency and stability of high-density ungraded tailings in deep cone thickeners (DCT). Laboratory flocculation tests were conducted to investigate the effects of unit consumption of different flocculants, the slurry concentration of ungraded tailings, and settling time on the thickening process. Based on the optimal parameters derived from laboratory experiments for high-density ungraded tailings, the commissioning, and operation of the DCT demonstrated excellent flocculation and sedimentation perfor-mance, validating the accuracy of the laboratory findings. The research confirms that determining optimal flocculation parameters ensures effective flocculation and thickening of high-density ungraded tailings in deep cone thickeners, providing robust technical and theoretical support for environmentally sustainable tailings management and resource-based utilization.