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It is difficult in the description of rock cuttings' lithology category with a traditional manual method since PDC bits have been widely used in the process of drilling. To recognize the tiny cuttings' lithology category effectively, a digital compact system based on high-resolution color linear CCD and microphotography is established and introduced in this paper. The system is mainly constructed by high resolution color linear CCD, micro lens, white LED light sources and conveyor. The Color linear CCD with up to 4080 pixels per line combined with micro lens leads to a resultant reproduction ratio of 1:1. It ensures that tiny cuttings' images can be captured clearly, and hence the detailed information of cuttings' color and texture can be obtained. With the linear scanning, we can get images with both high-resolution and larger field of view than array CCD. Optimal parameter configuration is determined by the experiments of hardware control program and optical parameter adjustment. The software to recognize cuttings' lithology category is developed by extracting multi-character values from the image information and by using the LIBSVM classifier. With the optimal parameter configuration and the developed recognition software, the cuttings' lithology category has been well described with a average recognition rate about 95% for mudstones and about 90% for sandstones, which proves that the cuttings' images captured by the high-resolution linear CCD meet the requirement of the subsequent recognition algorithm. The obtained results show that the digital compact system is greatly potential to be used in oil field logging.