Abstract: By analyzing the reactor operation data and experiment requirements,the digital centralized data acquisition system based on PCI bus is designed.The system synthetically makes the use of bus technology,electrical isolation,virtual instrument,Labwindows/CVI platform and ACCESS database,and achieves automatic data acquisition,failure alarm,data analysis,remote monitoring of radiation dose,and so on;Software design based on multi-layer architecture implements the interface display of operational status and the fault diagnosis,and improves the data acquisition for more visual and reliability.It is proved that the system is stable,reliable and secure.On the other hand,the practical operation is simple and easy to maintain.Furthermore,the digital centralized data acquisition system has enhanced the digitization and automation of data acquisition of the reactor,and meets the design requirements.