A kind of radar echo simulator hardware architecture based on PC and FPGA is proposed, it is extensible, programmable and suitable for upgrading, and the ballistic missile echo is generated based on such simulator. This paper builds up a ballistic model and an echo signal model on ballistic missile, the model-based analysis is presented and the analyses of the echo simulator and simulation signal source's test results are done. The result shows that the simulator can precisely and effectively simulate and generate ballistic missile echo signal.