In this paper, the design scheme, the signal flow and the selection of the radar echo signal processing board based on FPGA are studied. In view of the demand of the echo signal simulation, the design method of the function of the board is studied. Three key technologies of the design of digital instantaneous frequency measurement and storage time delay component and integer multiple interpolation are discussed in this paper. The program can achieve 1 GHz broadband radar echo signal simulation and adapt to pulse compression radar and SAR test requirements. This project has certain reference significance to the construction of related systems.