Abstract: Gas hydrates are known as a clean potential energy. About 99% gas hydrates occur in marine sediments and the vast majority of marine gas hydrates has no cover on the top. It means that traditional oil and gas mining technology can not be used for exploitation of gas from marine hydrates. This paper proposed a hydraulic transportation mining method for exploitation of shallow marine gas hydrates. The method suggests using hydraulic transportation equipment in the pipe mining system. The equipment includes a conveyance and a high pressure pump. According to the throughput of thermal decomposition of gas hydrate, a theoretical relationship between transmission system and hydrates decomposition rate was established. It is believed as a progress of exploitation of marine shallow hydrates and provides a theoretical basis for design of hydraulic conveyance equipment and containers.