Abstract: The electric dipole，as one of the basic models of electromagnetism，has an exotic field

distribution， which in the normal textbooks is given by either the gradient of the

electric potential or the vector superposition method. These mathematical approaches are

hardly helpful for students to understand the features and the unique picture of the

dipole field distribution. Here，based on an analog of the mechanical pendulum and the

electric di- pole，we give the two forms of the dipole field，especially the free-of-coordinate

one，and practical applications of this analog. Our paper can benefit beginners in seeing the inner

relation of knowledges，understanding the features of the dipole，and appreciating the power of

analogy thinking.

Key words: dipole, simple pendulum, electric potential, electric field intensity