A method for determining a packet dropping policy of a data packet, wherein the method comprises the following steps: • receiving, by a network device, the data packet transmitted in a network (S 101); • obtaining, by the network device, path information of the data packet from a source end to a destination end based on a source address of the source end and a destination address of the destination end of the data packet, wherein the path information is a total hop count of routers passed through by the data packet from the source end to the destination end (S 102), wherein the obtaining, by the network device, the path information of the data packet from the source end to the destination end based on the source address and the destination address of the data packet specifically comprises: ∘ calculating a first hop count of routers of the data packet from the source end to the network device based on a time to live value of the data packet, and finding a second hop count of routers from the network device to the destination end based on the destination address of the data packet and from a mapping relationship between the destination address and the second hop count of routers, and ∘ summing the first hop count and the second hop count, thereby arriving at the total hop count of routers passed through from the source end to the destination end, and • determining, by the network device, the packet dropping policy of the data packet based on the path information when network congestion occurs. • receiving, by a network device, the data packet transmitted in a network (S 101); • obtaining, by the network device, path information of the data packet from a source end to a destination end based on a source address of the source end and a destination address of the destination end of the data packet, wherein the path information is a total hop count of routers passed through by the data packet from the source end to the destination end (S 102), wherein the obtaining, by the network device, the path information of the data packet from the source end to the destination end based on the source address and the destination address of the data packet specifically comprises: ∘ calculating a first hop count of routers of the data packet from the source end to the network device based on a time to live value of the data packet, and finding a second hop count of routers from the network device to the destination end based on the destination address of the data packet and from a mapping relationship between the destination address and the second hop count of routers, and ∘ summing the first hop count and the second hop count, thereby arriving at the total hop count of routers passed through from the source end to the destination end, and ∘ calculating a first hop count of routers of the data packet from the source end to the network device based on a time to live value of the data packet, and finding a second hop count of routers from the network device to the destination end based on the destination address of the data packet and from a mapping relationship between the destination address and the second hop count of routers, and ∘ summing the first hop count and the second hop count, thereby arriving at the total hop count of routers passed through from the source end to the destination end, and • determining, by the network device, the packet dropping policy of the data packet based on the path information when network congestion occurs.