A technical scheme of word data co-transmit in the air-ground tactical data link system is presented. This scheme is based on CS-ACELP speech compress algorithm. In the limited channel bandwidth, multi-channel speech signals can be transmitted at the same time of data transmitting. In the scheme implementation, the two - order end recursion method is utilized to do the search computing for adaptive codebook, and the run efficiency of algorithm is greatly raised. In addition, the peripheral resources characteristics of DSP chip are taken into consideration, and an effective design is made for the hardware interface.