A lineless speech communication system is designed on the base of solar blind ultraviolet ray. The system has solar blind ultraviolet ray as its medium; it codes and decodes speech sound with the MBE technology, moderates signals with the 2FSK technology, and demoderates signals with the Zero-crossing Detection technology. Results show that the system is flexible and stable; its communication speed mounts to 9600it/s, and its coding error rate is only 0.0001 per cent within eyesight range of 200 meters. It can implement real-time speech communication and data transfer.