A new design of the digital broadcast system based on 3G means of transmission and a cloud computing is proposed to replace the traditional one, which has such disadvantages as the coverage restriction, the high covering and maintenance costs, frangibility to interference and poor capacity of emergency information dissemination. Consisting of three parts including the broadcast control platform, the control and the receiving terminal, the new system uses the 3G network infrastructure of Telecom to achieve grouping and fixed broadcasting, thus solving the urgent broadcasting issues in emergency. Experiments have shown that this system owns many advantages, such as resource pool, elastic supply, simplified terminal and rapid deployment.