The invention discloses a protecting intelligent central system orienting transformer substations and a cold and hot standby mode selection method thereof. According to the protecting intelligent central system, a collecting and processing module is used for collecting operating data of all the transformer substations, a communicating module, a fault position distinguishing module and a trip decision-making module are used for achieving analysis and calculation of the collected data, finally after station region protection of the transformer substations quits from maintenance, the protecting intelligent central system serves as a standby protecting system of the transformer substations with faults to replace the protection functions of the transformer substations with the faults, and therefore the reliability of load-center substation systems is effectively improved. Before the protecting intelligent central system is formally put into operation, cold and hot standby modes are selected, and serve as two working modes of the protecting intelligent central system, the cold standby mode is high in economy while low in reliability, the hot standby mode is high in reliability while low in economy, the protecting intelligent central system can make suitable selection for the transformer substation systems in different health states, and therefore balance between the economy and the reliability is achieved.