In the process of transition from traditional substation to smart substation，the monitoring difficulties brought by the change of substation network structure are reflected in the difficulty of efficient extraction of effective information and corresponding fault location and traceability in the huge database of secondary system condition monitoring in smart substation． Under this background，firstly，the change of substation network structure is discussed as well as the intelligence． Secondly， based on substation secondary condition monitoring system，the concept of monitoring and monitoring signals are analyzed． Finally，in order to solve the problem of processing massive data in smart substation，the advantages of Hadoop data processing platform，and the application and development of big data in smart substation are analyzed and summarized．