Abstract: Chinese Maifanite, a natural mineral from Naiman Banner, Tongliao City, Inner Mongolia Autonomous Region, has potential applications in water purification, environmental remediation, healthcare, and agricultural improvement. Weathering processes alter the physicochemical properties of Maifanite, thereby influencing its heavy metal adsorption performance. This research systematically investigated Maifanite samples collected from different depths in the southern mountainous mining area of Naiman Banner, conducted comprehensive analyses including weathering degree assessment, heavy metal adsorption experiments, and prevention and control mechanism studies combining physicochemical characterization. The research reveals that Naiman Banner Maifanite primarily undergoes physical weathering. Based on macroscopic characteristics, Chemical Index of Alteration CIA, and weathering coefficient Kf , deep-layer samples were identified as slightly weathered, while surface samples exhibited moderate to strong weathering. Weathering increased the specific surface area of Maifanite by 66.81%, reduced pores smaller than 3.6 nm, and increased pores between 3.6~4.0 nm from 12.36% to 40.05%. Additionally, weathering caused the destruction of quartz and plagioclase crystals, leaching of alkaline elements (Na, Mg, Si, K, Ca). The zero potential point shifted markedly from 7.09 to below 2. Notably, deep-layer Maifanite demonstrated preferential adsorption toward anionic chromium (Cr) -a characteristic groundwater contaminant-with a maximum theoretical adsorption capacity of 0.90 mg/g. Conversely, surface-weathered Maifanite exhibited enhanced adsorption capacity for cationic cadmium (Cd) -a typical soil pollutant-reaching 5.57 mg/g. The adsorption process, comprising three distinct stages (surface diffusion, mesopore diffusion, and micropore diffusion), achieved equilibrium within 24 hours. Multilayer heavy metal adsorption mechanisms were predominantly governed by electrostatic interactions with additional contributions from surface hydroxyl complexation. In conclusion, natural geological weathering induces significant physicochemical modifications in Maifanite, including the observed zero potential point shift, which collectively enhance its capacity for comprehensive heavy metal prevention and control in both soil and groundwater systems. This research provides crucial theoretical foundations for the sustainable development and utilization of Naiman Banner Maifanite in groundwater purification applications.