In order to improve the frequency measurement precision of digital receiver, an improved Rife frequency measurement algorithm was proposed base on the performance analysis of the Rife algorithm, and the principle of the algorithm and FPGA implementation steps were described in detail. The simulation results show that under the same signal to noise ratio (SNR), the improved Rife algorithm's error is less than that of the Rife algorithm. Meanwhile, in order to improve the operation speed, the look-up table in FPGA is used to achieve the logarithm operation and replace division by subtraction to make the frequency measurement speeds up to 240MHz. The experiment results demonstrate the effectiveness of the algorithm.