Abstract: To solve the line-of-sight problem when using multi-linear CCD cameras in large equipment(such as aerospace field) measuring process, a novel monocular 3D coordinate measurement method based on orthogonal cylindrical imaging was proposed. The system consisted of an orthogonal cylindrical imaging camera and an optical target. The measurement could be finished without multi-cameras intersection by using space resection. Measurement principle of orthogonal cylindrical imaging camera and intrinsic parameter calibration were analyzed. Structure parameter and calibration of optical target were designed. Measuring method with orthogonal cylindrical imaging camera and optical target was emphatically studied. Mathematical model of coordinate calculation was derived. In a 1 000 mm1 000 mm1 000 mm measurement volume that was 3 m away from the camera, the distance measurement accuracy of the proposed method was respectively better than 0.4 mm and 0.7 mm in the horizontal, height and depth direction. For coordinate measurement, the accuracy was better than 0.5 mm. Experimental results showed that the method was feasible and valid with good accuracy.