Urban cleaning work is done every day, but the results are not satisfactory. Mud, dust, and PM2.5 Are becoming more and more prominent in the information age. How to implement deep cleaning, in fact, we do not lack methods, what we lack may be awareness. An innocent clod of soil uses its own changes in the development of events to show how it eventually becomes PM2.5, In order to remind us to think about our urban cleanliness management.