In view of the natural gas hydrate reservoir environment and relying on the research on the geological survey project “the design and technical study on in-situ drilling and sampling equipments for the water formations”, pressure-temperature core sampler for ocean was developed. On the basis of laboratory test, functional marine experiment was made on the developed drilling tools in shallow water and deep water successively. After the improvement, the functional test of pressure-temperature core sampler was made in 1392m deep sea with success, which lays a solid foundation for the ocean exploration and sampling of natural gas hydrate in China.