Experiment teaching is an important part of biology learning in senior high school and an important link to improve students'' subject quality. Taking the experiment of detecting carbohydrate, fat and protein in biological tissues as an example, this paper uses the project-based learning theory as the guiding ideology, and guides students to adopt the way of division of labor and cooperation in groups. After many explorations and practices by teachers and students, the selection of experiment materials, operation methods and problems encountered in the experiment are reviewed and improved, a more concise method is found, students are guided to expand and explore more contents, and the confusion encountered by the students is solved through the experiment. And the methods learned in life, become the promoters of healthy life, practitioners for the same type of experiment to provide an example.