Abstract: It′s significant to detect the cracks of tunnel lining for tunnel disease detection. Aiming at the low auto? maticity, inefficiency, poor accuracy and likely missing of record in traditional tunnel lining crack detection technology, an experimental study on image acquisition method of tunnel lining is conducted based on line-scanning digital camera. The basic principle of line-scanning imaging under experimental conditions is introduced, a theoretical analysis and equipment selection of the experimental equipments and system integration are carried out, a test is conducted under experimental conditions, and image data acquisition of cracks of tunnel lining model is completed.The results show that the proposed image acquisition method can be applied to the image acquisition of tunnel lining cracks.