A method for transmitting data, the method comprising: transmitting, by a communication device, a signal in a switching duration between a downlink sub-frame and an uplink sub-frame to occupy a current channel; and transmitting, by the communication device, data over the current channel; characterized in that, when the communication device is a network device, start time of a signal transmission is start time of the switching duration, and there is a first interval between end time of the signal transmission and end time of the switching duration, where a length of the first interval is less than or equal to that of a preset interval of time, more than or equal to a smallest length of guard; or, when the communication device is a network device, then a sum of length of a second interval and a first interval is less than or equal to that of a preset interval of time, and the length of the first interval is more than or equal to a smallest length of guard; when the communication device is a User Equipment, UE, then the sum of the length of the second interval and the first interval is less than or equal to that of the preset interval of time, and the length of the second interval is more than or equal to the smallest length of guard; wherein the length of the first interval is a length of interval between end time of the signal transmission and end time of the switching duration, and the length of the second interval is a length of interval between start time of a signal transmission and start time of the switching duration; or, when the communication device is a User Equipment, UE, there is a second interval between start time of a signal transmission, and start time of the switching duration, wherein a length of the second interval is less than or equal to that of a preset interval of time, and more than or equal to a smallest length of guard; or, when the communication device is a User Equipment, UE, the signal is an uplink signal to be transmitted by the UE to a network device in an uplink sub-frame following an end of the switching duration, and a length of a second interval between start time of a signal transmission, and start time of the switching duration is less than or equal to that of a preset interval of time. transmitting, by a communication device, a signal in a switching duration between a downlink sub-frame and an uplink sub-frame to occupy a current channel; and transmitting, by the communication device, data over the current channel; characterized in that, when the communication device is a network device, start time of a signal transmission is start time of the switching duration, and there is a first interval between end time of the signal transmission and end time of the switching duration, where a length of the first interval is less than or equal to that of a preset interval of time, more than or equal to a smallest length of guard; or, when the communication device is a network device, then a sum of length of a second interval and a first interval is less than or equal to that of a preset interval of time, and the length of the first interval is more than or equal to a smallest length of guard; when the communication device is a User Equipment, UE, then the sum of the length of the second interval and the first interval is less than or equal to that of the preset interval of time, and the length of the second interval is more than or equal to the smallest length of guard; wherein the length of the first interval is a length of interval between end time of the signal transmission and end time of the switching duration, and the length of the second interval is a length of interval between start time of a signal transmission and start time of the switching duration; or, when the communication device is a User Equipment, UE, there is a second interval between start time of a signal transmission, and start time of the switching duration, wherein a length of the second interval is less than or equal to that of a preset interval of time, and more than or equal to a smallest length of guard; or, when the communication device is a User Equipment, UE, the signal is an uplink signal to be transmitted by the UE to a network device in an uplink sub-frame following an end of the switching duration, and a length of a second interval between start time of a signal transmission, and start time of the switching duration is less than or equal to that of a preset interval of time.