If wanting to get the ideal coring effect in the quaternary system and neogene , you must overcome the coring difficulties during drilling in flow model, RuanSu silt stratum , which are core block,washing out and disturbed samples etc. in the sand,Three layer tube coring drilling tool with bottom jet bit is mainly designed for quaternary loose and neogene, weak formation coring drilling and the structure is improved during drilling. The drilling tool is tested in the East China Sea the CSDP-2 holes in the quaternary, and it shows that the newly improved structure of the drilling tool could obtain the very good coring effect.