For the task requirements of dual band infrared search and tracking system,a multi core DSP software architecture based on master slave architecture is designed,which is based on the general signal processing hardware platform of multi core DSP,combined with the system functional requirements,algorithm requirements and hardware characteristics of multi core DSP. Search tracing algorithm and the application software design are implemented. Its application is verified in infrared search and tracking system. The experimental results show that it can meet the real time processing requirements of the system for dual band infrared image task function.