Abstract: To address the engineering challenges in coal preparation plants, including insufficient synergy between the reagent dosing system and the filter-press system in coal slurry water treatment, fixed reagent dosing ratios that fail to adapt to fluctuating coal quality and water quality conditions, this study takes the coal slurry water treatment system of Wangpo Coal Preparation Plant as the research object and investigates a collaborative fusion control strategy for the reagent dosing–filter-press system. Through coal slurry water sedimentation tests, the effects of flocculant and filter-aid dosages on sedimentation rate, sediment characteristics, and filter-press operation indicators were analyzed. Two interrelated parameters were introduced: the dosing ratio β of filter aid to flocculant and the effective filter-press feed time t. Based on a thickener underflow pressure threshold of 1.3 MPa, the operation was divided into two stages—low-pressure and non-low-pressure—and corresponding collaborative dosing–filter-press fusion control strategies were respectively established. The results show that after the coordinated control of the system, the overflow slurry concentration decreased from 325 mg/L to 280 mg/L, the underflow concentration increased from 375 g/L to 396 g/L, the filter-press feed time was shortened from 2715 s to 2456 s, and the filter cake moisture content decreased from 22.86% to 22.18%. Meanwhile, the dosages of filter aid and flocculant were reduced by 6.36% and 7.59% respectively, achieving an annual total reagent cost saving of 261000 yuan. The established collaborative fusion control system can overcome the limitations of traditional independent single-unit process control, simultaneously improve both thickening sedimentation and filter-press dewatering performance indicators, reduce reagent consumption and system energy usage, and provide a technical reference for intelligent renovation of coal slurry water treatment systems in similar coal preparation plants.