The construction parameters of deep cement mixing(DCM) on land and underwater soft foundation are usually determined by test pile,and the underwater DCM is mostly four-axis,so the construction parameters are difficult to determine.In this paper,the DCM piles in reclamation project is studied,the key parameters of the cement mixing pile,such as BRN,W-shaped construction curve at the bottom and cement slurry jet technology are studied,and the cement soil-cement strength is tested through triple tube coring.The results indicate that the cement content in the silt is optimized from 320 kg/m3 to 300 kg/m3,and the unconfined compressive strength of the cement-soil mixing pile is greater than 1.0 MPa after 28 days curing,which meets the design requirements.The pile’s strength can be improved by adding two W-shaped curve to remix the hard clay layer at the bottom.To fully stir the clay,the penetration speed should not be greater than 0.3 m/min and the withdraw speed should not be greater than 1.0 m/min.The stirring blade rotation speed should match the drill penetration or withdrawing speed to improve the mixing effect and the quality of pile.