The invention discloses a teaching aid. The teaching aid comprises a base and at least one protrusion block; the at least one protrusion block is arranged on the base; furthermore, one surface of theat least one protrusion block is bonded to one surface of the base; and a light emitting line is arranged at the intersection of adjacent two surfaces of the base and the at least one protrusion block. The light emitting line can outline the contour of the teaching aid; when different directional structures of the teaching aid are displayed to students, the graph displayed by the light emitting line is the corresponding view graph of the teaching aid; the three-view intuitional effect and the visual experience effect of the teaching aid are improved; and the learning difficulty of the studentsand the teaching difficulty of a teacher are reduced.