Abstract: The sediments in the Shenhu sea area of the South China Sea is composed of sand and cohesionless soil, and their mechanical properties have a significant impact on the stability of ocean engineering. The compression characteristics of the cohesionless soil with sand is one of the important contents of the studies of its mechanical properties. In order to analyze the compression characteristics of soil samples under different loads, the isotropic compression tests of cohesionless soil samples with different sand contents and different initial void ratios are carried out by using the high-pressure triaxial apparatus test system. The test results show that under the high effective stress, the cohesionless soil has significant transition soil properties, and the initial fabric is difficult to be changed. With the increase of the content of the porous fragile calcareous sand, the compressibility and the convergence of the compression curve of the soil sample increase, and the crushing of calcareous sand significantly changes the initial fabric. A mathematical model is proposed to describe the compression characteristics of the cohesionless soil with sand, and the physical meaning of fitting parameters is clear and easy to determine. Compared with the different soils compression tests data, it is found that the model results also are in a good agreement with those of other kinds of sands, which verifies the extensive applicability of the model. Compared with the existing compression models, the practicability of the model is verified. The results can provide a basis for analyzing the stress-strain relationship of cohesionless soil.