A method for controlling switching network traffic in a switching card including a plurality of input ports and a plurality of output ports, the switching card receiving unicast and multicast cells from a plurality of line cards via the plurality of input ports, scheduling the received unicast and multicast cells and sending the scheduled unicast and multicast cells to the plurality of line cards via the plurality of output ports, characterized in that the method comprises: step 1: monitoring, by a congestion-monitoring module, both a length of a unicast virtual output queue and a length of a multicast virtual output queue of the unicast and multicast cells received from the plurality of line cards via the plurality input ports, in real time, and when the length of one of the queues exceeds a congestion threshold, recording the queue as a congestion queue, generating a congestion indication signal and sending it to a counter-pressure module; and adding, by the counter-pressure module, a congestion identifier to a header of every cell to be outputted via a corresponding output port to a corresponding line card, so as to notify the corresponding line card to control its traffic to be sent to the switching card; step 2: transmitting, by the congestion-monitoring module, a notification message of cell entering/leaving queue to the counter-pressure module, when it is found from the real-time monitoring that there is a cell received via one of the plurality of input ports entering/leaving the congestion queue; and step 3: determining, by the counter-pressure module, whether a number of cells in the congestion queue that are received via the input port reaches a pre-determined threshold according to the notification message of cell entering/leaving queue, and if it does, adding, by the counter-pressure module, an indication signal of active link level traffic control to the header of every cell to be outputted via the corresponding output port to the corresponding line card, so as to notify the corresponding line card to stop its corresponding traffic to be sent to the switching card; wherein the counter-pressure module maintains a unicast cell congestion counter and a multicast cell congestion counter for each input port; and the notification message of cell entering/leaving queue comprises: an indication message of incrementing the unicast cell congestion counter of the corresponding input port by one when it is found that there is a unicast cell entering the queue; an indication message of decrementing the unicast cell congestion counter of the corresponding input port by one when it is found that there is a unicast cell leaving the queue; an indication message of incrementing the multicast cell congestion counter of the corresponding input port by one when it is found that there is a multicast cell entering the queue; and an indication message of decrementing the multicast cell congestion counter of the corresponding input port by one when it is found that there is a multicast cell leaving the queue. step 1: monitoring, by a congestion-monitoring module, both a length of a unicast virtual output queue and a length of a multicast virtual output queue of the unicast and multicast cells received from the plurality of line cards via the plurality input ports, in real time, and when the length of one of the queues exceeds a congestion threshold, recording the queue as a congestion queue, generating a congestion indication signal and sending it to a counter-pressure module; and adding, by the counter-pressure module, a congestion identifier to a header of every cell to be outputted via a corresponding output port to a corresponding line card, so as to notify the corresponding line card to control its traffic to be sent to the switching card; step 2: transmitting, by the congestion-monitoring module, a notification message of cell entering/leaving queue to the counter-pressure module, when it is found from the real-time monitoring that there is a cell received via one of the plurality of input ports entering/leaving the congestion queue; and step 3: determining, by the counter-pressure module, whether a number of cells in the congestion queue that are received via the input port reaches a pre-determined threshold according to the notification message of cell entering/leaving queue, and if it does, adding, by the counter-pressure module, an indication signal of active link level traffic control to the header of every cell to be outputted via the corresponding output port to the corresponding line card, so as to notify the corresponding line card to stop its corresponding traffic to be sent to the switching card;