Abstract: Palladium （Pd） is widely used in aerospace, automotive exhaust catalysis, and chemical and pharmaceutical industries due to its excellent catalytic activity and chemical stability. To address the challenges of low selectivity and high cost in existing recovery processes for palladium catalysts, this study prepared an amino-thiourea-functionalized activated carbon adsorption material via a grafting method for highly efficient and selective adsorption of Pd（II） from aqueous solutions. Using activated carbon as the carrier, amino-thiourea was grafted onto its surface through amide bonds, successfully fabricating the adsorption material （AC-NS）. Fourier Transform Infrared Spectroscopy （FTIR） and X-ray Photoelectron Spectroscopy （XPS） characterization results confirmed the successful grafting of amino-thiourea. Adsorption experiments demonstrated that at the optimal pH = 4, the adsorption capacity of AC-NS for Pd（II） was significantly enhanced, reaching three times that of pristine activated carbon. The adsorption behavior followed pseudo-second-order kinetics and the Freundlich isotherm model, with a theoretical maximum adsorption capacity of 235.65 mg/g, and the process was spontaneous and endothermic. In mixed solutions containing Pd（II）, Cu（II）, Ni（II）, Co（II）, and Zn（II）, AC-NS exhibited excellent selectivity toward Pd（II）, with its adsorption capacity far exceeding those of other coexisting ions. X-ray Diffraction Analysis （XRD） and XPS analyses indicated that Pd（II） adsorption on AC-NS occurred through the formation of coordination bonds with N and S atoms, enabling its separation from mixed metal ion solutions. This study provide an important reference for the efficient and selective recovery of palladium from complex systems.