The invention provides a substation secondary system data information analysis system. The time and space distribution characteristics of the data of the secondary system of a substation are divided according to the sources of the data. Then, the constraint relations of the data information are analyzed, the information redundancy relation and constraint relation are extracted longitudinally in space dimension, and the information constraint relation is extracted transversely in time dimension. The time and space distribution characteristics and the constraint relations can be used to intelligently diagnose the correctness and effectiveness of data in secondary equipment monitoring and maintenance. The technical scheme starts with the time and space distribution characteristics of the data information of the secondary system of the substation, and fits in with the features of a networked secondary system. Meanwhile, in the technical scheme, more specific and richer information can be provided for on-line monitoring and fault diagnosis of the secondary system by making use of the information constraint relations. In addition, the specific space dimension and time dimension of a fault can be located quickly according to the time and space distribution characteristics of the data information, and the efficiency of operation and maintenance can be improved.