The CCD star sensor is a kind of higher accuracy and more advanced technology of attitude sensitive equipment which observes fixed star as benchmark, and it is widely used on satellite attitude control system. It has many advantages which includes high precision, high sensitivity, no attitude accumulative error and so on. This paper describes how to design and develop a signal processing system (SPS) based on FPGA (Field Programmable Gate Array) for CCD star sensor. Above all, an integrated solution to a signal processing system is put forward briefly, which contains the design of system architecture and system function. Secondly, Some Key technologies of design and implementation are described in detail, which contain these designs of data stream, instructions stream, multi-clock data processing and triple modular redundancy (TMR). In practice, hardware and system tests have been carried out, and the results prove that the SPS is reliable and stable, and it has been used successfully in CCD start sensor.