Natural gas hydrate is an important strategic exploitation resource in the future， which has been widely concerned by all countries in the world. Therefore， large-scale exploitation of subsea natural gas hydrate is inevitable. At present， the exploitation of subsea natural gas hydrate is still in the trial production stage， and so far no mature mining method has been formed. Starting from the problems caused by non-diagenetic that people are worried about during the exploitation of marine natural gas hydrate， such as large-scale gasification of subsea hydrate， destruction of marine ecological environment and submarine geological disasters， this paper analyzes the safety of the exploitation of marine natural gas hydrate， investigates the present situation of the exploitation of marine natural gas hydrate in the world， points out that reservoir stimulation is the only way for large-scale exploitation of marine natural gas hydrate in the future， and explores the feasibility of reservoir stimulation with modifying foamed cement slurry by hydraulic jet while drilling horizontal wells with hydraulic jet micro hole technology， which lays a foundation for the commercial exploitation of gas hydrate in China.