An intelligent POE power source supplying system comprises a PSE device and a plurality of PD devices. The PSE device comprises a POE power module, a POE control unit, a micro-control unit, a power supplying pre-processing unit and a power supplying arbiter. The POE power module is connected with the power supplying pre-processing unit. The output end of the power supplying pre-processing unit is respectively connected with the input end of the POE control unit and the input end of the power supplying arbiter. The output end of the power supplying arbiter is connected with a main control unit which is connected with the POE control unit. The output end of the POE control unit is provided with a plurality of power supplying ports connected with the PD devices. According to the intelligent POE power source supplying system, the product cost is effectively reduced, one low-end POE chip is enough in the technical scheme, and it is enough that the chip has the basic detecting and power supplying functions. The power utilizing rate of the system is high, and when the system power supplying is not enough, the number of the power supplying ports of the system is maximal, and the power output is maximal.