The invention discloses a nuclear reactor system, particularly an accelerator driven ceramic fast reactor (ADCFR) system. The system comprises a high-current superconducting linear accelerator, a gravity-driven high-power dense particle spallation target and a full-ceramic fast neutron reactor. The system is subjected to external source drive by the accelerator. The spallation target generates neutrons, so that the reactor carries out a nuclear reaction in a subcritical state. After preset time, the external source drive of the accelerator is stopped, so that the reactor is transformed to operate in a critical state. The structures in the reactor core of the reactor are made of ceramic materials.