Radiation hardened electronics is a crossed and compositive subject whose radiation effects, mechanisms of radiation damage, hardening methods,test methods and simulation methods are very important for electronic system working in extreme environment. All kinds of damage effects produced by neutrons,gamma and X-rays from nuclear explosions and energetic particles from space and atmosphere are systemically hackled which includes dose rate effect,total ionizing effect,single event effect and displacement effect. The development of synergistic damage effects between radiation and environment and among different kinds of radiation are introduced in detail, including atom transfer effect on photocurrent,damage difference among single irradiation,serial irradiation and coinstantaneous irradiation of neutron and gamma ray,damage difference among proton,X-ray and neutron irradiation and synergistic effect between hydrogen and gamma irradiation. Technique evolvement of nuclear explosive,space and atmosphere radiation hardening is expatiated on. The ground test equipments and simulation software capabilities of nuclear,space and atmosphere radiation effects are summarized. Finally, the potential challenges and key techniques in the field of radiation hardened electronics after the 2020s are prospected.