Tracing back to the source, the literal translation of "grassroots" from English began in America in the19th century. At that time, the United States was immersed in a gold rush, and it was rumored that there was gold on the top of the mountainous soil with rich grassroots. Therefore, when the word "grassroots" was introduced into the field of sociology, it was given the connotation of "grassroots people". In fact, grass roots have two meanings: one is the power relative to the government or decision makers; One refers to the disadvantaged groups corresponding to the mainstream, elite culture or elite class. In my opinion, the basic meaning of "grassroots" is "bottom-up" and "local", which has local flavor, rich life consensus and full of fresh vitality. Compared with large-scale research, small-scale research belongs to the category of school-based research and is an important and feasible way of school-based teaching and research. Grass-roots research on small topics does not need to be initiated, mid-term exams or final reports, and it emphasizes teachers' conscious actions. The so-called "small" means: the research scope is microscopic, the content is specific, the incision is small, the cycle is short, and it is easy to operate. The purpose of small-scale research is mainly to solve the problems and puzzles in teachers' personal education and teaching, and to sum up experience. It is not mainly a theoretical research, but a microscopic applied research. Teachers themselves are researchers. The research content can be a chapter or a topic in the teaching process, and the phenomena, cases and problems existing in education and teaching. The research results can be summary reports, demonstration classes, teaching designs, teaching papers, etc. The research period in Xian Yi ranges from a few months to one school year, several school years and so on. It can be learned by one or more people. Reading, recording, reflection and action can be used flexibly, and there is no need to deliberately require the full use of a certain research method. In a word, the characteristics of "grassroots" small projects can be summarized by "small", "near", "real" and "true". "Small" means starting with small things, small phenomena and small problems, and seeing the big ones from the small ones. Similar to "research on improving students' participation in classroom teaching." "Close" means close to teaching, close to reality, not too grand, such as "research on mathematical application problems", "research on the transformation of students with learning difficulties" and "research on improving students' self-analysis and diagnosis ability of mathematical errors". We should abandon the big and empty description and prediction and pay more attention to it. Similar to "how to remember the names of students" and "how to rank." "Truth" means true research, discussion, writing and practice. To sum up, the research on "grass-roots" small topics is teachers' self-study, which takes the problems that teachers urgently need to solve in their own education and teaching as the research object, takes problem solving and experience summary as the research goal, absorbs and uses all kinds of experience, knowledge and methods that are conducive to solving problems, improves education and teaching, and at the same time improves education and teaching level and promotes teachers' professional development.