The invention provides a graphite/manganous oxide composite electrode material. The composite electrode material is a graphite/manganous oxide composite electrode material with a nuclear shell structure; the nuclear shell is nanosphere, and the core of the nanosphere is manganous oxide with grain size less than 100nm; and the shell of the nanosphere is a graphite carbon layer with thickness less than 10nm. The invention also relates to a preparation method of the electrode material, a product of the electrode material, and application.