In order to improve the ranging accuracy between satellites and increase the available bandwidth of systems in the simulation and tests, a design algorithm for high-accuracy fractional delay filter based on the boundary fitting Remez algorithm was proposed. The proposed algorithm used the polynomial approximation thought of Farrow structure to fit the impulse response boundary coefficients of the filter designed by Remez algorithm, and achieved fractional delay filters through the polyphase decomposition. The proposed algorithm achieved continuous impulse response boundary when high-order filters was used, while the group delay error was reduced and the accuracy was improved. The simulation results show that the proposed algorithm improves the accuracy of fractional delay filters a little, doubles the available bandwidth and reduces the number of multipliers need to be used.