Abstract: Against the backdrop of global environmental governance, pollutants in the environment have now ubiquitously reached trace levels, necessitating the development of highly efficient advanced treatment processes. Adsorbent materials have emerged as one of the key materials in water pollution control due to their high adsorption capacity, stability, practicality, and environmental friendliness. Accurate evaluation of the performance of adsorbent materials is a fundamental prerequisite for enhancing pollution treatment efficiency. Material characterization techniques, as critical means for elucidating adsorption mechanisms, play a central role in assessing the adsorption performance of such materials. Based on domestic and international research findings in the field of water pollution control using adsorbent materials, this study systematically summarizes the role of key characterization techniques in clarifying the mechanisms of adsorbent materials. The research reveals that the current system of characterization techniques primarily encompasses the following three dimensions: (1) micromorphology and pore structure, such as scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area and pore size distribution analysis; (2) chemical composition and functional group analysis, such as Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS); and (3) crystal structure and phase analysis, represented by X-ray diffraction (XRD). The study also prospects future directions for the development of characterization techniques, with the aim of providing theoretical support and technical references for performance optimization of adsorbent materials, design and development of novel materials, and their efficient application in water pollution control.