The paper presents a FPGA-based airborne IF acquisition system, by using the reserved analog I/O port for IF monitoring, to facilitate the test and analysis of IF modulated signal. Using the Cyclone II EP2C35F672I8 in FPGA as the core processing chip, only a single FPGA device can realize the data caching of high-rate data flow, high-speed data storage and CPCI bus data transfer. Experimental results show that the IF acquisition system will provide a valuable reference to data and analysis for future debugging and analysis in the process of the development and test of a function.