Due to the low undrained shear strength of soft soil foundation, subsea pipelines penetrate into seabed under self-weight after laying. The penetration prediction of the subsea pipeline，which will connect to the spool is of great significance for proposing safe and efficient methods for connecting them. This work aims to propose the penetration prediction method for pipeline on soft clay by combining numerical simulation and model tests. Based on the Coupled Eulerian-Lagrangian (CEL) method, finite element models for the penetration of subsea pipelines in soft soil foundation was established in this work, comprehensively considering the soil shear strength. The impact of different scaling ratios on the pipeline penetration was analyzed so that a method to extrapolate the penetration of prototype pipelines based on scaled-down pipeline penetration is proposed. In addition, model tests of pipeline penetration on soft clay were carried out with different scales based on similarity scaling theory to verify the numerical extrapolation method.