In order to reduce the effect of draft on imaging quality of space optical camera, the reason and compensation method of draft are analyzed, and influence of draft on space camera is studied. An adjusting mechanism to compensate draft is designed for a space camera. Bidirectional screw driving is adopted to adjust draft of focal plane of the camera, enabling the draft adjusting mechanism having characteristics high strength and stiffness, compact, and good stability. Finite element analysis shows that the mechanism has high stiffness and dynamic strength. Accuracy of the mechanism are measured by closed-loop method and compared before and after the vibration tests. The results indicates that the accuracy of the mechanism is superior to 1′, and the range of draft adjusting is superior to +5°～-5°, fulfilling the designrequirements and achieving high accuracy of image motion compensation.