The invention discloses a signal transmission device comprising a housing, a bottom shell arranged at the bottom of the housing, and a surface shell arranged on the top of the housing. A protection cover, a display module, a bracket, a battery module, a cable buckle, a decoding board and an output board are arranged inside the housing successively from top to bottom. A WiFi module and at least twocommunication modules are arranged on the housing; a first WiFi antenna and a second WiFi antenna are arranged inside the WiFi module; and a main communication antenna and a sub communication antennaare arranged in the communication module. According to the invention, with the WiFi module and at least two communication modules, the data transmission rate of the signal transmission device is increased and phenomena of interruption and a screen fault during a live broadcasting process of the user are avoided.