A backpressure method of a multistage switching network, comprising: receiving, by an intermediate switching node (S2, 7), first backpressure information from a lower stage switching node, and characterized in that the first backpressure information is classified into a first global backpressure information and a first queue backpressure information; and in the further steps of: if the received backpressure information comprises the first global backpressure information, stopping sending, by the intermediate switching node, a corresponding data packet received from an upper stage switching node to the lower stage switching node, and not sending the first global backpressure information to the upper stage switching node and if the first backpressure information comprises the first queue backpressure information, sending, by the intermediate switching node, the first queue backpressure information to the upper stage switching node and continue sending, by the intermediate switching node, a corresponding data packet received from the upper stage switching node to the lower stage switching node, wherein the lower stage switching node has a buffer, and the global backpressure information indicates that the number of packets in said buffer reaches or exceeds a certain threshold, and wherein the packets in said buffer of the lower stage switching node are queued according to certain rules to form multiple queues and wherein the queue backpressure information indicates that the length of a queue reaches or exceeds a certain threshold. receiving, by an intermediate switching node (S2, 7), first backpressure information from a lower stage switching node, and characterized in that the first backpressure information is classified into a first global backpressure information and a first queue backpressure information; and in the further steps of: if the received backpressure information comprises the first global backpressure information, stopping sending, by the intermediate switching node, a corresponding data packet received from an upper stage switching node to the lower stage switching node, and not sending the first global backpressure information to the upper stage switching node and if the first backpressure information comprises the first queue backpressure information, sending, by the intermediate switching node, the first queue backpressure information to the upper stage switching node and continue sending, by the intermediate switching node, a corresponding data packet received from the upper stage switching node to the lower stage switching node, wherein the lower stage switching node has a buffer, and the global backpressure information indicates that the number of packets in said buffer reaches or exceeds a certain threshold, and wherein the packets in said buffer of the lower stage switching node are queued according to certain rules to form multiple queues and wherein the queue backpressure information indicates that the length of a queue reaches or exceeds a certain threshold. if the received backpressure information comprises the first global backpressure information, stopping sending, by the intermediate switching node, a corresponding data packet received from an upper stage switching node to the lower stage switching node, and not sending the first global backpressure information to the upper stage switching node and if the first backpressure information comprises the first queue backpressure information, sending, by the intermediate switching node, the first queue backpressure information to the upper stage switching node and continue sending, by the intermediate switching node, a corresponding data packet received from the upper stage switching node to the lower stage switching node, wherein the lower stage switching node has a buffer, and the global backpressure information indicates that the number of packets in said buffer reaches or exceeds a certain threshold, and wherein the packets in said buffer of the lower stage switching node are queued according to certain rules to form multiple queues and wherein the queue backpressure information indicates that the length of a queue reaches or exceeds a certain threshold.