Abstract: Based on the exploration of the recycling and harmless treatment of waste liquid produced during the experimental process,the waste liquid released in some experiments was classified and collected,and four metals such as Hg,Pb,Cr,Ag,acid and alkali waste were used as harmless treatment objects,and then they were tested and recycled.In the project,students designed and optimized the solution of waste liquid by themselves.Through the experimental teaching mode of student-orientation and teacher assistant,the good experimental habits of students were expected to be cultivated,and the students’ experimental skills were improved.Meanwhile,the students environment awareness were strengthened.