PROBLEM TO BE SOLVED: To provide a radiation imaging system and a radiation imaging method for preventing a failure of a radiation imaging device from being generated when irradiation with a radiation is performed in a state in which preparation of the radiation imaging device is not prepared.SOLUTION: A radiation imaging system comprises: a radiation imaging device 102 which has an irradiation detection unit 104 for detecting irradiation with a radiation and images a radiation image based on the radiation and a control unit 108 for controlling the radiation imaging device 102. When the irradiation detection unit 104 detects irradiation with a radiation in an imaging preparation state set depending on lapse time from refresh operation of a photoelectric conversion element in the radiation imaging device 102, the control unit 108 makes the photoelectric conversion element in the radiation imaging device 102 perform refresh operation.
