Objective Space radiation is an important environmental factor affecting the health and efficiency of astronauts.To explore the effects of radiation on electroencephalogram(EEG)signal,and to provide references for further study of the effects of radiation on Central Nervous System(brain)injury.Methods The resting state EEG of radiotherapy volunteers were collected before and after X-ray exposure.The effects of radiation on EEG was studied by means of spectral analysis,nonlinear dynamic characteristic analysis,correlation coefficient analysis and microstate analysis.Results The results show that radiation induced a"slow wave"phenomenon in the EEG spectrum,with a decrease in Gravity Frequency,Sample Entropy,and Lempel-Ziv Complexity,and an increase in Fatigue Index.The average duration and frequency of EEG microstate C both significantly decreased,and the proportion of time for microstate D decreased,while the average correlation coefficient between microstates A and C increased.Conclusion A decrease was induced by radiation in neuronal excitability,which may affect cognitive brain networks and brain attention.This study can provide reference for the study of radiation damage to the Central Nervous System(brain).