Abstract: With the fast development of the CT technology, real-time data acquiring and fast image reconstruction as a advanced capability in a Cone-beam CT system are more frequenfly requested. Therefore to transfer projection data from the detector unit to the computing unit in a fast and stable way becomes one of the key points in today's design of CT systems. In this paper we proposed a high speed data transmission solution based on Ethernet interface and Linux OS in which a transfer caching system is introduced. Test results show that such application has significant merits in solving the data loss problem while transferring from CT sampling module to the PC. Being with a low cost yet high stability and efficiency, it can be practically useful to the similar fast data acquiring system for image reconstruction.