Abstract: In the time synchronization process of smart substation,there is one noteworthy problem that the delay jitter of paths in the time-synchronization communication network may cause the degradation of the synchronization precision.Therefore,this paper proposed an IEEE 1588 synchronization time-delay optimization method.Firstly,this paper analyzes the course of the synchronizations error caused by delay jitter of paths in the environment of smart substation,which aims to implement the quantitative analysis of the synchronization error mechanism.Secondly,based on the framework of IEEE 1588 protocol,the proposed method is depicted to operate the second time’s compensation using an optimal estimation of delay jitter of paths,which is calculated by a time-delay extending measurement mechanism to compress the synchronization’s influence from delay jitter of paths.Finally,the proposed method is verified by an experiment based on the typical end-to-end transparent clock synchronization mode of IEEE 1588 protocol in smart substation.The simulation results show that the proposed method may achieve better time synchronization performance in terms of precision and stability for slavery clocks in smart substation.