To impart self-healing ability to epoxy, styrene-loaded and benzoyl peroxide–loaded microcapsules were prepared by in situ polymerization in emulsion using melamine–formaldehyde resin as the wall former. Afterward, the two types of microcapsules were embedded in epoxy to produce self-healing epoxy composite. Upon fracture of the material, the core substances in the broken capsules were released and polymerization of styrene initiated by benzoyl peroxide took place, rebinding the cracked planes. The parameters for manufacturing the microcapsules and the factors that influence healing efficiency of the system were discussed in detail.