针对卫星导航系统时间同步需求，提出了导航卫星双向伪距时间同步的理论根据，并就4种基本同步方法（双向无线电伪距同步方法, 星地双向激光伪距同步方法,双向卫星中继无线电伪距同步方法, 双向地球站中继无线电伪距同步方法）与应用进行了分析，与目前国际导航卫星时间同步通用方法相比,具有精度高, 方法简单，设备负担轻特点。

Aiming at the demand of time synchronization, the navigation satellite two-way clock pseudo range time synchronization was presented and the application of four basic synchronic ways were analysed in this paper. Comparing with other navigation satellite clock synchronization ways, this way was provided with advantages such as high precision, simplicity and light burden to equipment on satellite and so on. In the first section of the paper the meaning and status of time synchronization of navigation satellite clock were discussed. The error of the navigation satellite clock synchronization affects users' position and precision directly. In the second section two way pseudo range time synchronization theory was introduced, that is to get time error between two stations that is satisfied with the condition △t_AB =-t_Br-t_Ar. t_Ar and t_Br are the time of A and B station( or satellite) that receives another station ( or satellite)'s transmitting signal. The difference between them is clock bias. In the third sections pseudo range time synchronization ways introduced. In the fourth, fifth and sixth section of the paper, two way radio pseudo range(TWRPr), two way laser pseudo range(TWLPr) ,two way satellite-relay pseudo range (TWSrPr), and two way earth-relay pseudo range ( TWErP) were analyzed respectively. TWRPr way was provided and RMS = 0.42 ns. TWSrPr three stations time synchronization result was RMS =1.75 ns. In the eighth section the precision that two ways pseudo range time synchronization can reach was summed up, that is TWRPr can reach 1.0 ns. The repeated precision of TWLPr can reach 0.1 ns, and can be used to evaluate the capability of atomic clock and validate the precision of other synchronization method.