Abstract: SAR imaging puts forwards higher speed of imaging which can hardly be accomplished by single DSP and how to make multiple DSPs to work in parallel is still a problem. This paper proposes a design called virtual single-node based on TMS320C6678 for SAR applications，which can make full use of the processing capabilities, input-output capabilities and storage capabilities supplied by multiple DSPs. A storage technique is also introduced in this project which can access the two dimensions of a matrix with a high speed according to experimental tests. In this paper, a virtual single-node consisted of four TMS320C6678 applied with Range-Doppler algorithm is achieved, and the effectiveness of virtual single-node design is verified.