The invention discloses a fixed radiation monitoring system. The system comprises a control part, at most eight detectors and an ionization chamber, the detectors are located on the ionization chamberand connected with the control part, and the detectors are one or more selected from a low-range gamma detector, a wide-range gamma detector, a NaI gamma detector, a high-range gamma detector and a neutron detector. Thus, the structure is simple, the stability is high, the energy response is sound, the dose rate range is wide, the angular response and cosmic ray response are sound, and the mechanical property is reliable; and the system can work for a long time, does not reduce the monitoring performance due to the working time, and can be applied to measurement and real-time alarm of the environment X-gamma external irradiation air absorption dose rate and neutron dose equivalent, dose rate monitoring alarm of a radiation diagnosis and treatment workplace, monitoring of a medical X-ray machine and an industrial radioactive source, dose rate monitoring of an underground radiation environment, and the like.