星敏感器是一种通过观测恒星位置，直接提供运载体在惯性空间中三轴绝对姿态的光电仪器。星图处理是星敏感器的重要工作内容之一，关系到后续星图识别的正确进行。处理方法需要能够有效地降低噪声，抑制背景，并正确提取出图像中的恒星目标。从分析星敏感器实际获取的星图特性入手，提出了相对应的图像处理算法。最后，进行实际测星试验，验证了星图处理算法的正确性和有效性。

Star sensor is an electro-optical instrument used to provide the absolute 3-axis attitude with respect to the celestial sphere of a craft utilizing star observations. The image processing is important to the star sensor. The result of the image processing has an impact on the star identification. The image processing is required to be capable of depressing the image noise and background and detecting the star in the image. The star image from the star sensor is analysed in this paper. The model of the image processing based on the star sensor is set up. A star observation experiment based on star sensor is carried out. Validity of the model is confirmed.