A voice communication device includes a frame generating module, a setting module and a transmitting-receiving module. The frame generating module is used to generate a plurality of data frames, each data frame includes four time segments with a same duration, and each time segment includes synchronous information, physical address information, and voice data coding information. The setting module is used to set two time segments in each data frame as a data transmitting phase, and set remaining two time segments as a data receiving phase. The transmitting-receiving module is used to transmit and receive data for realizing the voice communication with other voice communication devices. The present invention also provides a relay device and a voice communication method. According to the invention, a full duplex voice communication is realized so that wireless data transmitted by various voice communication devices does not conflict mutually. The voice communication device, the relay device and the voice communication method not only solve a transmission and distribution problem for transmitting wireless data, and but also realize the remote voice transmission based on a Zigbee technology so as to provide a great convenience for users.