A system and a method for implementing warm-up scanning in a CT device are provided. The method includes: closing a slot of a beam limiter before a warm-up scanning process is initiated implementing the warm-up scanning process to a CT radiation source and opening the slot of the beam limiter after the warm-up scanning process is finished. The target object may not need to move during the warm-up scanning process. Therefore, a second time scout image scanning is no longer necessary and extra ionization radiation may be avoided.
