A channel access method is provided. Under the method, a network element performs random backoff listen before talk (LBT) for channel preemption, and after the preemption succeeds, performs signal transmission in the first transmission time interval TTI within a maximum channel occupancy time MCOT. The network element also performs nonrandom backoff LBT for channel preemption before another at least one TTI within the maximum channel occupancy time MCOT.