Abstract: With the increasing research on the use of adsorbent materials for the removal of trace water pollutants, accurate evaluation of their adsorption performance has become crucial. Material characterization techniques, as key methods for revealing adsorption mechanisms, are essential for assessing the adsorption properties of adsorbent materials. Based on over 4 000 domestic and international papers published in the last five years on adsorption materials for water pollution control, this review systematically summarizes the main categories of characterization techniques, their technical principles, and application limitations. It focuses on three aspects—microscopic morphology and pore structure, chemical composition and functional groups, and crystal structure and phase composition—to discuss research progress in the physical adsorption behaviors of pollutants, chemical adsorption mechanisms, the distribution of active sites, and structural stability of materials. It also analyzes the current status and typical cases of multi-technique synergistic characterization, while projecting research hotspots and future trends in this field. The results indicate that scanning electron microscopy (SEM) provides intuitive characterization of adsorbent surface morphology, while the BET specific surface area and pore size distribution method quantitatively determines specific surface area and pore size distribution, both providing key parameters for evaluating physical adsorption capacity. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDS) respectively analyze functional groups, elemental chemical states, and distribution, aiding in elucidating chemical adsorption mechanisms. X-ray diffraction (XRD) identifies crystalline phase composition and structure, allowing for the monitoring of phase evolution before and after adsorption. Currently, individual characterization techniques have unique advantages in revealing specific properties of adsorbent materials, but each has inherent limitations and cannot independently provide a comprehensive analysis of complex adsorption mechanisms. Against this backdrop, characterization techniques are trending toward multi-technique synergy, micro-area analysis, and in-situ characterization. Finally, future characterization technical development should focus on establishing a systematic framework for synergistic multi-technique integration and cross-validation, to more comprehensively and accurately reveal the structure-performance relationship of materials.