The research findings of brain science have been widely used in various fields. The in-depth study of brain science can help to develop brain potential and creativity efficiently, thus effectively improving the quality of teaching. In order to optimize mathematics teaching, this paper conducts the research on brain science-based mathematics education and teaching design. Through the theoretical analysis of brain science and the analysis for complex relationships in the process of mathematics teaching, combined with the characteristics of mathematics, this paper discusses the relationship between symbolic mathematics, situational mathematics and linguistic mathematics and its application in mathematics education, and also explores the mathematics teaching design and implementation based on brain science. The research results of this paper shall provide scientific theoretical support for creating a suitable mathematics teaching environment, and further promote the scientific and efficient development of mathematics teaching.