A method for controlling an air interface resource, comprising: sending, by a first communication device, a hello packet to a second communication device over a first communication channel at a first frequency after an access network device allocates an air interface resource to the first communication channel, wherein the first communication channel is a communication channel, which passes through the access network device, between the first communication device and the second communication device; detecting, by the first communication device, whether service data is transmitted over the first communication channel by using the air interface resource; switching, when it is detected that the service data is not transmitted over the first communication channel by using the air interface resource, the first frequency of sending the hello packet to the second communication device to a second frequency of sending the hello packet to the second communication device, wherein the first frequency is higher than hello packet detection frequency of the access network device, and the second frequency is lower than the hello packet detection frequency of the access network device; and sending a first frequency switching message to the second communication device, wherein the first frequency switching message is used for instructing the second communication device to switch the first frequency of sending a hello packet to the first communication device to the second frequency; wherein the first communication device is a core network device and the second communication device is user equipment; or the first communication device is user equipment and the second communication device is a core network device. sending, by a first communication device, a hello packet to a second communication device over a first communication channel at a first frequency after an access network device allocates an air interface resource to the first communication channel, wherein the first communication channel is a communication channel, which passes through the access network device, between the first communication device and the second communication device; detecting, by the first communication device, whether service data is transmitted over the first communication channel by using the air interface resource; switching, when it is detected that the service data is not transmitted over the first communication channel by using the air interface resource, the first frequency of sending the hello packet to the second communication device to a second frequency of sending the hello packet to the second communication device, wherein the first frequency is higher than hello packet detection frequency of the access network device, and the second frequency is lower than the hello packet detection frequency of the access network device; and sending a first frequency switching message to the second communication device, wherein the first frequency switching message is used for instructing the second communication device to switch the first frequency of sending a hello packet to the first communication device to the second frequency; wherein the first communication device is a core network device and the second communication device is user equipment; or the first communication device is user equipment and the second communication device is a core network device.