After analysis of Tacan signal structure, an idea of adding data-broadcast function on Tacan beacon is proposed in view of low occupancy rate of uplink channel. The maximum time can be used for broadcasting data per second is estimated according to response probability. A method of broadcast identification code and geodetic coordinate of beacon is then designed, in which information is encoded as pulse train and inserted after main reference pulse group. The simulation and analysis results show that the method has no influence on angle measurement performance, and the bandwidth of signal eradiated by beacon maintains within 300 kHz. The response probability of beacon is merely reduced by 0.2% when the data broadcasting function is added.