A Space-Target IR Tracking System has been designed.The hardware and software structure are introduced.The system is designed based on ADI-TS201 DSP and the software is designed based on VDK core.According to the characteristics of Space-Target IR image,background image is subtracted from the source IR image at first,then adaptive threshold is adopted,Kalman filter is used to estimate the track of the target.It turns out that the design can meet the requirement to track the space targets in real time.