This title describes the primary business information DAB and function of the transmission channel,presents a design module which is used in DAB transmitters to transport the text messages in main business information channel.Because of the demand of diversity,real-time and economy when transmitting text messages by DAB,we utilize adaptive packet mode transport mechanisms that is based on the MOT protocol transmission specification to improve the DAB transmitting system to send text messages(weather warning information,traffic information,etc.) flexibility and capacity utilization of sub-channels.Currently,the program has been achieved by the adaptive block coding software.