The photopolymerization of epoxides initiated with iron-arene complex features initiation at lower temperatures and propagation at higher temperatures. The appropriate heat treating temperature is around 80℃. Increasing the light intensity to certain level can accelerate the polymerization. Monofunctional reactive diluents at a concentration of 10%～20% may be used. Bifunctional reactive diluents offer faster reaction rates than the monofunctional ones. Triethylene glycol divinyi ether(TGDVE) was found to have excellent toughening effect.