An inspection system includes: a radiation source; a detector configured to detect a signal when radiation emitted by the radiation source acts on an inspected object; and a processor in communication connection with the radiation source and configured to select a periodic radiation combination corresponding to a type of the object according to the type of the object, and cause the radiation source to emit radiation to the object in the selected periodic radiation combination during the time that the object is scanned, and the periodic radiation combination is a chronological arrangement of radiation pulses output by the radiation source in each scanning period, and radiation pulses have at least two different radiation energies. The system is capable of improving adaptability and simplifying control. An inspection method is also provided.