An inspection system for synchronously positioning radioactive material, comprising: a scanning and imaging apparatus comprising a ray source configured to generate an X-ray and a detection device configured to receive an X-ray transmitted through an inspected object, wherein the ray source is configured to image the inspected object by emitting the X-ray to the inspected object; and a radioactivity detector configured to detect whether the inspected object comprises radioactive material synchronously with the process of scanning implemented by the scanning and imaging apparatus (110, 150), wherein in a case that the radioactivity detector detects radioactive material, the inspection system is configured to mark an actual position of the radioactive material in an X-ray image of the inspected object obtained by the scanning and imaging apparatus (110, 150), characterized in that while the scanning and imaging apparatus (110, 150) starts to scan the inspected object, the radioactivity detector is configured to start to detect and record a scanning start time; and when radioactive material is detected, the radioactivity detector is configured to transmit a time interval from a time when the radioactive material is detected to the scanning start time to the scanning and imaging apparatus (110, 150) as a warning start time of the radioactive material, and when it is detected that radiation of the radioactive material ends, the radioactivity detector is configured to transmit a warning peak time and a warning end time to the scanning and imaging apparatus (110, 150) respectively, and then the scanning and imaging apparatus (110, 150) is configured to calculate the actual position of the radioactive material in the image of the inspected object based on the scanning start time, the warning start time, the warning peak time, and the warning end time; wherein the warning peak time is a time interval from a time when a peak value of the radioactive material is detected by the radioactivity detector to the scanning start time, and the warning end time is a time interval from a time when no radioactive material is detected by the radioactivity detector to the scanning start time. a scanning and imaging apparatus comprising a ray source configured to generate an X-ray and a detection device configured to receive an X-ray transmitted through an inspected object, wherein the ray source is configured to image the inspected object by emitting the X-ray to the inspected object; and a radioactivity detector configured to detect whether the inspected object comprises radioactive material synchronously with the process of scanning implemented by the scanning and imaging apparatus (110, 150), wherein in a case that the radioactivity detector detects radioactive material, the inspection system is configured to mark an actual position of the radioactive material in an X-ray image of the inspected object obtained by the scanning and imaging apparatus (110, 150), characterized in that while the scanning and imaging apparatus (110, 150) starts to scan the inspected object, the radioactivity detector is configured to start to detect and record a scanning start time; and when radioactive material is detected, the radioactivity detector is configured to transmit a time interval from a time when the radioactive material is detected to the scanning start time to the scanning and imaging apparatus (110, 150) as a warning start time of the radioactive material, and when it is detected that radiation of the radioactive material ends, the radioactivity detector is configured to transmit a warning peak time and a warning end time to the scanning and imaging apparatus (110, 150) respectively, and then the scanning and imaging apparatus (110, 150) is configured to calculate the actual position of the radioactive material in the image of the inspected object based on the scanning start time, the warning start time, the warning peak time, and the warning end time; wherein the warning peak time is a time interval from a time when a peak value of the radioactive material is detected by the radioactivity detector to the scanning start time, and the warning end time is a time interval from a time when no radioactive material is detected by the radioactivity detector to the scanning start time.