Disclosed is a scanning device using radiation beam for backscatter imaging. The scanning device includes a radiation source; a stationary shield plate and a rotary shield body positioned respectively between the radiation source and the subject to be scanned, wherein the stationary shield plate is fixed relative to the radiation source, and the rotary shield body is rotatable relative to the stationary shield plate. The ray passing area permitting the rays from the radiation source to pass through the stationary shield plate is provided on the stationary shield plate, and ray incidence area and ray exit area are respectively provided on the rotary shield body. During the process of the rotating and scanning of the rotary shield body, the ray passing area of the stationary shield plate intersects consecutively with the ray incidence area and the ray exit area of the rotary shield body to form scanning collimation holes. Further, a scanning method using radiation beam for backscatter imaging is also provided.