The utility model discloses a DSP based radio self-adaptive modem which is characterized by comprising a digital interface unit, a processing unit (ARM), a DSP unit and an analog interface unit. The modem has the advantages that a software radio technology including self-adaptive modulation and demodulation in the different rates and modulation manners including 2400bps-MSK, 9600bps-QPSK, 19200bps-16QAM and 38400bps-16QAM is employed, so that different system and onsite conditions can be adapted, bandwidth reduction and self-adaptive equalization algorithms of the baseband signals are used, the compatibility with different types and performances of radio stations in system reconstruction is improved, and other high-speed modulation and demodulation manners can be flexibility expanded and upgraded under the condition that the cost is not increased.