The application of contact method in primary school mathematics refers to the concrete application of problem chain method in teaching. In primary school mathematics teaching, teachers should not only explain knowledge, but also test students' learning effect by asking questions. It is used to deepen the understanding of a mathematical concept, that is, to introduce different forms of similar properties and concepts under the same proposition conditions, so as to make the understanding deeper and the connotation richer. Problems can be solved in the form of problem chain.