The invention discloses a digital radio broadcast signal transmission method which is a transmission scheme of mixing a time domain and a frequency domain. According to the digital radio broadcast signal transmission method disclosed by the invention, a low-complexity peak-to-average power ratio reduction technology, a serially concatenated multi-code rate punctured convolution code modulation technology and a signal frame time-frequency domain combined iteration separation treatment technology are designed aiming at the technical problems of high signal peak-to-average power ratio and channel fading noises of a broadband multi-carrier digital radio broadcast transmission system, which need to be solved, and therefore the broadband multi-carrier digital radio broadcast transmission systemhas the advantages of low peak-to-average power ratio, short synchronization time, fading noise influence resistance, controllable multi-service, and the like.