Abstract: In crewed lunar and deep-space exploration missions, accurate characterization of plume environments is critical to spacecraft system design, extraterrestrial landing/ascent planning, and space-environment adaptability verification, ensuring mission precision, efficiency, reliability, and safety. This paper first outlines fundamental plume effect assessment methodologies, then reviews global advances in both numerical simulation and experimental validation techniques. The plume-related challenges encountered during lunar and deep-space landing/ascent are systematically analyzed. Targeted solutions and strategic research recommendations are proposed, providing actionable guidance for (1) upcoming crewed lunar missions, and (2) plume effect prediction, evaluation, and mitigation in deep-space spacecraft design.