This paper focuses on the practical application of the idea of "learning by doing" in primary school science education, takes the Big Dipper teaching AIDS as an example, and discusses its improvement and innovation in the teaching process. As an auxiliary tool, the Big Dipper teaching AIDS aim to improve students' ability of observation, operation and thinking, but there are still some deficiencies in practical application. At present, the Big Dipper teaching AIDS in teaching materials have some problems, such as single production materials, inflexible structure and insufficient use, which limit their application effect in the concept of "learning by doing". Therefore, this paper puts forward the improvement measures of teaching AIDS, including the selection of more environmentally friendly materials, the optimization of structural design and the enrichment of use methods. After the improvement of the Big Dipper teaching AIDS, in the actual teaching significantly enhance the interest of students, effectively