Environment-responsive smart membranes consist of two components: a porous membrane substrate and a polymeric functional switch that senses external environmental stimuli. Through external environmental stimuli, the physical and chemical properties of the smart membrane are altered, thereby enabling active regulation of separation performance or other functionalities. Due to their unique properties, environment-responsive smart membranes have been widely applied in various fields and are currently a research hotspot. This paper adopts a combination of quantitative and qualitative research methods to analyze the changing trend in patent applications, the distribution of major source countries, the ranking of major applicants, and the comparison of application volumes across different technical branches in the field of smart membrane technology. Furthermore, it provides a detailed analysis of key technologies, including the LCST phase transition characteristics of temperature-responsive membranes, imprinting and coating techniques for molecularly responsive membranes, three directions of light-responsive membranes—photoactuators, photochromism, photocatalysis, as well as graft blending and response sensitivity enhancement for pH-responsive membranes. The research shows that China is the major source country for environment-responsive smart membrane patent applications, with universities being the main applicants and enterprises accounting for a relatively low share. Temperature-responsive, molecularly responsive, light-responsive, and pH-responsive smart membranes are the key research and development directions. To this end, future efforts should focus on developing bio-stimuli-responsive membranes and biomimetic membranes, continuously optimizing the performance of temperature and pH-responsive membranes, expanding the applications of light-responsive membranes, promoting the functional transformation of molecularly responsive membranes, and accelerating industrial transformation through industry-university-research collaboration.