在水下多线阵地震勘探系统中,同步采样非常重要.针对传统水下多线阵地震勘探系统同步采样方法复杂,变采样率后锁定时间长等问题,构建了一种基于主从同步模型的非锁相环本地时钟异步驱动的高精度同步采样改进模型,提出了利用采集节点本地异步驱动时钟短时稳定性与本地采样时钟主从同步校准相结合的高精度同步采样方法.基于同步采样改进模型,分析了时钟稳定性、传输延时、相位抖动等因素对同步采样误差的影响规律,并据此提出了传输延时逐级补偿的同步采样误差高精度校准方法.所建构模型及方法从原理上有效消除了相位抖动对同步采样误差的影响,有效补偿了信号传输延时对同步采样误差的影响,同时大大简化了同步采样的软硬件实现难度,解决了传统方法变采样率后锁定时间长的问题.利用搭建了双线阵阵列同步采样实验系统进行验证,达到了优于5 ns的同步采样精度.“,”Synchronous sampling is very essential in underwater multilinear array seismic exploration system in which every acquisition node(AN)samples analog signals by its own analog-digital converter(ADC).Aiming at the problems of complex synchronous sampling method and long locking time after varying sampling rate in traditional underwater seismic exploration system,an improved synchronous sampling model based on the master-slave synchronous model and local clock asynchronous drive with non phase locked loop(PLL)is built,and a high-precision synchronous sampling method is proposed,which combines the short-term stability of local asynchronous driving clock with the master-slave synchronous calibration of local sampling clock.Based on the improved synchronous sampling model,the influence of clock stability,transmission delay and phase jitter on synchronous sampling error is analyzed,and a high-precision calibration method of synchronous sampling error based on step-by-step compensation of transmission delay is proposed.The model and method effectively realize the immunity of phase jitter on synchronous sampling error in principle,and compensate the influence of signal transmission delay on synchronous sampling error.At the same time,it greatly reduces the complexity of software and hardware implementation of synchronous sampling,and solves the problem of long locking time after changing the sampling rate in traditional methods.The experimental system of synchronous sampling for dual linear array is built,and the synchronous sampling accuracy is better than 5 ns.