Education does more than give students facts; it develops their potential and trains them to adapt to and improve their living environment. Through education, students formulate informed ideas about the interactions between people, things, and the environment. In an era of global environmental change, students must understand environmental problems and develop the knowledge and skills to help mitigate or solve them. The key concepts students learn and the ideas that influence students during wetland ecology-based outdoor education courses are thus worthy of investigation. This study summarized several key indicators through a literature review and an analysis of expert interviews. The literature review revealed nine indicators: ecological conservation, natural environment, biological habitat, individual development, environmental education, learning through practice, social culture, economy, and environmental quality. An expert questionnaire was used to apply interpretive structural modeling and integrate correlations among the indicators. Subsequently, the analytic network process was employed to establish the weights of assessing indicators. This study defined key indicators and provided analysis of the weighted results. These findings give teachers an academic basis for enhancing the design of related teaching curricula to achieve their teaching goals effectively.