Abstract: Presently The algorithm of two-way satellite time transfer is one of the time synchronization methods with the highest accuracy.On the basis of two-way satellite time transfer algorithm,the characteristics of the propagation delay of two-way time transfer signals between moving satellite varying with intersatellite range were analyzed,and the rule of satellite clock offset varying with intersatellite range obtained with this algorithm was deduced.This paper presents a dynamic two-way time transfer algorithm with which high-accuracy intersatellite clock offset is solved through the combination of intersatellite pseudo-range polynomial fitting and clock-offset polynomial fitting.Simulation data of actual satellites showed that with the algorithm the intersatellite time synchronization error can be controlled within 5ns.As a result the algorithm can be used for intersatellite high-accuracy time synchronization.