In order to turn the dark corner into a bright and pleasant campus space and having the spirits of the World Toilet Day and SDGs' item 6, which both were held by UN, this study used purposive sampling technique and three schools in A City, which joined the plan for the renovation of old toilets in public elementary and junior high schools that K-12 Education Administration in Ministry of Education implemented, were selected as an example from the perspectives of overall configuration, construction methods, and space aesthetics. A School replaces the male and female toilet spaces so that each other can get the most comfortable toilet space. B School replaces the cement wall with a light steel column and glass to create a light and breathable toilet space. C School uses the local straw culture to create a hot spring-style toilet experience. The study also analyzes the key points of toilet improvement in the three schools and put forward some parts for reference.