A high speed data gathering system is designed for the seismic data acquisition system. CPCI crate is applied as the framework of the data gathering system. The number of the sample channels can be easily changed by plugging in or out the cards of the CPCI crate. Data can be gathered with high speed through the PCI bus of the CPCI crate. The use of DMA transferring simplifies the system control and improves the data gathering speed from multi-cards. Large cache is used to eliminate dead time of data gathering and improve the efficiency of DMA transaction. The experiment shows this system can satisfy 4 cables system, totally 7680 channels, requirements for data gathering system. This system features simple structure, high speed of data transferring, high performance of real-time data gathering, and can be easily applied to the other large scale data acquisition system.