This disclosure provides a backoff counting method in a non-simultaneous transmit and receive (NSTR) operation mode and the communication device for the method. The method includes: configuring a plurality of backoff counters for counting backoff slots with no medium activity of channels of the plurality of links; synchronizing a count value of a first backoff counter of the plurality of backoff counters with a count value of a second backoff counter of the plurality of backoff counters, if the first backoff counter starts counting later than the second backoff counter or resumes counting after a pause, wherein the count value of the second backoff counter is smaller than that of the first backoff counter; and transmitting or receiving a signal on a channel of at least one of the plurality of links after all the backoff counters reach a predefined value.