Operating principle and developing procedures of a time-domain measuring system of radar target are introduced. Digital Sampling Oscilloscope is used for measuring in compact range for the first time. The theory of time domain measurement was studied and the structure of the system and flow diagram for measuring were given. Programs for controlling of the oscilloscope and turntable as well as data processing were developed, based on which an entire measuring system of UWB compact range is achieved. Finally, some data measured and processed by the system are presented.