Electromagnetism course contains the dialectical materialism ideological elements. How to imperceptibly infiltrate the dialectical materialist viewpoint and method into the teaching process of electromagnetism is discussed through the combination of specific teaching cases, so as to promote the ideological and political connotation construction of electromagnetism course. This not only enables students to deeply understand and master the nature and law of electromagnetic phenomena, but also helps students to establish the world outlook of dialectical materialism and enhance their dialectical thinking ability.