Embodiments of the present application provide a method, device and system for controlling an air interface resource and relates to the field of communications, which improves air interface resource utilization. The method includes: when a core network device or user equipment detects that service data is not transmitted over a communication channel between the two devices by using an air interface resource, switching a first frequency of sending a hello packet to a peer device to a second frequency, and sending a frequency switching message to instruct the peer device also to switch the first frequency of sending a hello packet to the second frequency, so that when the hello packet is not detected within a packet detection period, an access network device releases an air interface resource occupied by a first communication channel.