The invention discloses an unattended transformer substation intelligent flood prevention system. The unattended transformer substation intelligent flood prevention system comprises a sensing layer, anetwork layer, a supporting layer and an application layer, wherein site analog quantity is converted into digital quantity through the sensing layer which can be processed by a computer, a site water quantity condition is uploaded to the supporting layer through the optical fiber connection and the wireless connection through the transmission on the network layer, through cloud computing, Internet of Things access and big data analysis, the site rainfall is comprehensively analyzed and processed and uploaded to the human-computer interaction interface of the application layer for operation.The system is used for solving the problems that accumulated water is much and the drainage is slow in flood season in an unattended transformer substation, and meanwhile, the adaptability that data exchange cannot be achieved between the flood season site condition and a control center, site duty personnel cannot acquire the site flood situation and timely discovery and treatment cannot be carried out when drainage equipment fails or a dangerous case occurs is taken into consideration.