Abstract: Aiming at the characteristics and test requirements of airborne weapons, the transverse adaptive digital filter (ADF) was built with least mean-square error (LMS) algorithm based on the analysis of ADF structure and optimization evaluation, and according to the design process of field programmable gate array (FPGA). The simulation result and application show that the ADF can realize the automatic adjustment of the weight coefficient vector and adapt to the characteristics of signals by creating 512kB random-access memory (RAM) space in FPGA. Since the LMS algorithm can get the best result in 0.1ms, the ADF designed in this paper can satisfy the test system of airborne weapons and the signal test error is less than 5%.