The hydraulic reclamation technology without cofferdam is the most ideal and rapid process for land formation in open sea areas.According to mature experience in hydraulic reclamation of sandy soil without cofferdam，developing efficient and reliable hydraulic reclamation technology of clay without cofferdam is an important direction to improve the efficiency of hydraulic reclamation in open sea areas with muds.Based on a shoreline restoration project in Lianyungang，this paper proposes the hydraulic reclamation technology without cofferdam，in which the traditional mud material is replaced by a lump hard earth cake.In addition，the paper compares multiple schemes in the field test section，repeatedly adjusts construction parameters，and improves the natural drainage and settlement efficiency of soil by hydraulic reclamation.The results show that the soil layer formed based on the hydraulic reclamation of clay lumps settles rapidly within 4-5 d after hydraulic reclamation，and the main consolidation is basically completed，enabling the construction machinery to enter the site safely.After 2.5 months of natural consolidation and settlement，the bearing capacity of the foundation by hydraulic reclamation can reach more than 45 kPa.The hydraulic reclamation of clay lumps facilitates land formation，and it is conducive to energy saving，carbon reduction，and ecological and environmental protection，thus having a good application prospect.