Abstract. As one of the key technologies of radar electronic warfare systems, Digital Instantaneous Frequency Measurement (DIFM) technology need to measure signals intercepted quickly. The traditional method of instantaneous frequency measurement is to translate the frequency information into phase information to complete the measurement of the frequency. This paper presents a modified phase measurement method which uses CORDIC algorithm, which is suitable for implementation in FPGA for avoiding using the multipliers. On this basis, the frequency of the signal can be calculated, using MATLAB simulation tool to test its performance, and finally, this method is implemented in the FPGA simulation. The simulation results show that this method has high accuracy, good benefits instantaneous frequency measurement for single-frequency signal, suitable for modern electronic warfare digital receiver digital instantaneous frequency measurement needs.