The invention relates to a segmented in-band modulation method for FM (frequency modulation) radio band digital analog mixed signals, in which analog sound broadcasting signals and digital sound broadcasting signals are combined to digital analog mixed signals which share an FM band. The FM band includes a plurality of sub-bands. For the digital sound broadcasting signals, sub-carriers are set to zero in an intermediate sub-band, or only synchronization symbol sub-carriers are retained; modulation modes in different orders are used in other sub-bands, and the distribution of sub-carriers of the sub-bands forms mirror symmetry to the center of the sub-bands, that is, the higher the modulation order is, the farther the distance is to the center. The synchronization symbol sub-carriers of the digital sound broadcasting signals are equally spaced and are modulated in an order lower than 24. Sound data symbol sub-carriers of the digital sound broadcasting signals are modulated in an order lower than 24 in a sub-band where the potential of analog signals is higher than 3.5 mu V. On the contrary, the sound data symbol sub-carriers of the digital sound broadcasting signals are modulated in an order higher than or equal to 24. The segmented in-band modulation method for FM radio band digital analog mixed signals has the advantages that the demodulation signal-to-noise ratio and the distortion index of analog signals of an FM digital analog mixed system are obviously improved, and the interference of digital analog signals in band same-frequency broadcasting signals is effectively eliminated.