Abstract:The south Yellow Sea continental scientific drilling project is carried out in Quaternary and Neogene strata, according to the strata characteristics, multifunctional agent (MBM) and anti-salt copolymer (GTQ) were chosen as the main agents for indoor experiments to prepare flushing fluids. The suitable formula of flushing fluids was selected for Quaternary and Neogene strata drilling and applied in the offshore drilling site of CSDP-02, it is proved that the MBM seawater flushing fluids have good effects, which ensures the smooth drilling construction in Quaternary and Neogene strata.