Abstract: In order to increase precision of frequency estimation for multi-section sampled signals and extend applicable range of the existing methods,a fusion method of multi-section signals with the same length and known frequency-shift is proposed.In the algorithm,some techniques such as parameter matrix for frequency-domain analysis,phase-difference compensating factor matrix and search frequency array are provided to solve such problems as unequal measured fre-quencies and phase discontinuity among different section signals.Four properties are given as mathematical justification of the proposed method.Simulated experiments with different application environment parameters are carried out.The results show that the presented algorithm is suitable for various types of multi-section signals with the same length and known frequency-shift,and with good noise immunity,its precision of frequency estimation is much higher than that of the existing methods.