This paper introduces the operational principle of Spaceborne Synthetic Aperture Radar （SSAR）. The System Design Project of SSAR is discussed here in detail. The most important factors in the design are related with the selection of Pulse Repeating Frequency （PRF）

Doppler bandwidth

transmit and nadir interference restriction

range and azimuth ambiguity

ground swath

data transfer rate etc. Because SSAR generates a large volume of data

we can’t process these data with ordinary computer. DAWN 1000 Parallel Processing System is introduced and utilized to simulate the SSAR system. Finally

the simulation result is given

which proves the correctness of the SSAR System Design Project.