The invention provides a sound data transmission system, which comprises a channel encoder, a data modulator and a loudspeaker, wherein the channel encoder is used for receiving and encoding a bit signal and generating an encoded signal; the data modulator is used for receiving the encoded signal and modulating the encoded signal into a sound signal with the frequency being located in a frequency band; the sound signal comprises at least four different sub sound signals, the frequency band comprises at least four sub frequency bands with different frequencies, and frequencies of the at least four sub sound signals are located in the at least four sub frequency bands respectively; and the loudspeaker is used for playing the sound signal comprising the at least four sub sound signals simultaneously. The sound data transmission system and the sound data transmission system improve the data transmission speed through efficient frequency block segmentation and through using a modulation mode that multiple frequencies are transmitted simultaneously. In addition, the sound data transmission method further improves the security of data transmission by being combined with error detection and encoding mode correction so as to achieve an application of carrying out wireless short-distance data transmission by using sound.