The invention relates to the technical field of an electric power system, and specifically relates to a digital intermediate-frequency structure of a multichannel data transmission radio station. The structure includes: through a software radio method, multipath narrowband signals are merged to a path of signals sent through a broadband transmitter; multipath data sharing broadband radio frequency synthesized by the intermediate frequency is sent; in the receiving direction, broadband signals received by an air interface are received through a broadband radio frequency unit, and a high-speed AD performs sampling; and the data is separated by employing the software radio method at the intermediate frequency to obtain wanted data. According to the structure, a single main station or a slave station can simultaneously support multiple channels; the system aggregates and separates the multichannel data at the intermediate frequency by employing the software radio technology and the digital intermediate frequency technology and shares the radio frequency unit of one broadband; one main station can simultaneously process multiple accessed slave stations so that the capacity of the main station is increased by times; and compared with the prior art, the data acquisition efficiency and the operating efficiency are substantially improved.