A method for transmitting a Common Public Radio Interface, CPRI, signal by means of a coaxial line, comprising: - converting (101; 301; 501) a Common Public Radio Interface CPRI signal sent by a sending end into a parallel data stream; and - extracting (102; 302; 502) valid data from the data stream by performing frame parsing; wherein extracting valid data from the data stream comprises separating user plane data, control and management plane data, and synchronization and timing data in the data stream by performing frame parsing; characterized in that the method further comprises the following steps: - converting the valid data into a transmittable analog signal, modulating the analog signal to a specified frequency, and sending the analog signal to a receiving end by means of a coaxial line, wherein converting the valid data into a transmittable analog signal and modulating the analog signal to a specified frequency comprises the steps of: - performing higher order modulation on the user plane data and up-converting the data onto a specified frequency to obtain a first modulation signal; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a second modulation signal; and - combining the first modulation signal and the second modulation signal into one signal, or the steps of: - separating the user plane data into multiple antenna carrier AxC signals, and up-converting each of the AxC signals onto a specified frequency; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a third modulation signal; and - combining each of the AxC signals and the third modulation signal into one signal. - converting (101; 301; 501) a Common Public Radio Interface CPRI signal sent by a sending end into a parallel data stream; and - extracting (102; 302; 502) valid data from the data stream by performing frame parsing; wherein extracting valid data from the data stream comprises separating user plane data, control and management plane data, and synchronization and timing data in the data stream by performing frame parsing; characterized in that the method further comprises the following steps: - converting the valid data into a transmittable analog signal, modulating the analog signal to a specified frequency, and sending the analog signal to a receiving end by means of a coaxial line, wherein converting the valid data into a transmittable analog signal and modulating the analog signal to a specified frequency comprises the steps of: - performing higher order modulation on the user plane data and up-converting the data onto a specified frequency to obtain a first modulation signal; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a second modulation signal; and - combining the first modulation signal and the second modulation signal into one signal, or the steps of: - separating the user plane data into multiple antenna carrier AxC signals, and up-converting each of the AxC signals onto a specified frequency; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a third modulation signal; and - combining each of the AxC signals and the third modulation signal into one signal. - performing higher order modulation on the user plane data and up-converting the data onto a specified frequency to obtain a first modulation signal; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a second modulation signal; and - combining the first modulation signal and the second modulation signal into one signal, or the steps of: - separating the user plane data into multiple antenna carrier AxC signals, and up-converting each of the AxC signals onto a specified frequency; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a third modulation signal; and - combining each of the AxC signals and the third modulation signal into one signal. - separating the user plane data into multiple antenna carrier AxC signals, and up-converting each of the AxC signals onto a specified frequency; - performing higher order modulation on the control and management plane data and the synchronization and timing data, and up-converting the data onto a specified frequency to obtain a third modulation signal; and - combining each of the AxC signals and the third modulation signal into one signal.