To meet the requirements of a Computed Radiography (CR) and to implement its functions, a new high-performance laser scanning system was designed. A scanning arm was designed which was composed with pentagonal prism and scanning object lens. Scanning arm is used to replace the Fθ lens. To cooperate with scanning arm, a circular imaging plate transport mechanism was designed. Scanning arm can receive stimulation luminescence as a receiving device, too. The system designed by this method has simple structure and good performance. Besides, the control scheme was introduced and timing sequence diagram of control system was given. The Influence of pentagonal prism’s displacement errors on system’s resolution was calculated. The calculation results show that this system is easily adaptive to the error. Experiments were carried out to verify the performance of laser scanner. Moreover, the results indicate that the images have good visual effect and can meet requirements of industrial inspection.