A power control method applicable to a power over Ethernet system, implemented by a power sourcing equipment in the system, comprising: determining whether there is a target powered device that needs to be connected to the power over Ethernet system; when it is determined that there is a target powered device that needs to be connected to the power over Ethernet system, calculating a sum of actual power of all powered devices that are currently powered on to obtain a total required power; determining whether the total required power exceeds a preset second power threshold, if the total required power exceeds the preset second power threshold, powering off a powered device that is currently powered on according to priorities corresponding to port numbers of all the powered devices that are currently powered on until the total required power is less than the preset second power threshold; if the total required power does not exceed the preset second power threshold, determining whether to power on the target powered device according to a preset first power threshold, wherein the preset second power threshold is greater than the preset first power threshold; characterized in that, determining whether to power on the target powered device according to the preset first power threshold comprises: determining whether the total required power exceeds the preset first power threshold in the power over Ethernet system, and if the total required power does not exceed the preset second power threshold and is greater than the preset first power threshold, determining whether a priority corresponding to a port number of the target powered device is the lowest; if the priority of the target powered device is the lowest, rejecting powering on the target powered device; and if the priority of the target powered device is not the lowest, selecting a powered device to be powered off from powered devices that are currently powered on and have priorities lower than the priority of the target powered device, powering off the selected powered device to be powered off and powering on the target powered device when a sum of actual power of powered devices that are not selected and the maximum power of the target powered device is less than or equal to the preset first power threshold. determining whether there is a target powered device that needs to be connected to the power over Ethernet system; when it is determined that there is a target powered device that needs to be connected to the power over Ethernet system, calculating a sum of actual power of all powered devices that are currently powered on to obtain a total required power; determining whether the total required power exceeds a preset second power threshold, if the total required power exceeds the preset second power threshold, powering off a powered device that is currently powered on according to priorities corresponding to port numbers of all the powered devices that are currently powered on until the total required power is less than the preset second power threshold; if the total required power does not exceed the preset second power threshold, determining whether to power on the target powered device according to a preset first power threshold, wherein the preset second power threshold is greater than the preset first power threshold; characterized in that, determining whether to power on the target powered device according to the preset first power threshold comprises: determining whether the total required power exceeds the preset first power threshold in the power over Ethernet system, and if the total required power does not exceed the preset second power threshold and is greater than the preset first power threshold, determining whether a priority corresponding to a port number of the target powered device is the lowest; if the priority of the target powered device is the lowest, rejecting powering on the target powered device; and determining whether the total required power exceeds the preset first power threshold in the power over Ethernet system, and if the total required power does not exceed the preset second power threshold and is greater than the preset first power threshold, determining whether a priority corresponding to a port number of the target powered device is the lowest; if the priority of the target powered device is the lowest, rejecting powering on the target powered device; and if the priority of the target powered device is not the lowest, selecting a powered device to be powered off from powered devices that are currently powered on and have priorities lower than the priority of the target powered device, powering off the selected powered device to be powered off and powering on the target powered device when a sum of actual power of powered devices that are not selected and the maximum power of the target powered device is less than or equal to the preset first power threshold.