A system and method for radiation inspection on a moving object. The system comprises a radiation source and a radiation detector. Rays emitted by the radiation source are limited in a scanning area. The scanning area is provided by a first boundary surface and a second boundary surface. The system also comprises: multiple detection units (110, 120, 130, 140, 150, 160) arranged along a detection channel in turn and used for triggering and sending a signal when detecting that the moving object arrives or leaves; and a control module used for receiving signals sent by the multiple detection units (110, 120, 130, 140, 150, 160) and controlling the radiation source according to the received signal. The first to third detection units (110, 120, 130) among the multiple detection units (110, 120, 130, 140, 150, 160) are located at one side of the scanning area and near the first boundary surface. The fourth to sixth detection units (140, 150, 160) among the multiple detection units (110, 120, 130, 140, 150, 160) are located at the other side of the scanning area and near the second boundary surface. The system and the method can implement radiation inspection on moving objects travelling in multiple directions.