Abstract: With the continuous global demand for energy， offshore oil and gas production is gradually expanding into deep and ultra-deep water areas. In this application context， the J-lay system demonstrates inherent adaptability in deepwater regions. This study develops a numerical simulation method for the J-lay technique based on the Winkler and macro-element models. The method utilizes finite difference methods to simulate its mechanical characteristics under nonlinear seabed conditions accurately. Feasibility is validated through a comparison with analytical solutions and model experiments. The research explores the impact of varying water depths and laying angles， revealing that increased water depth results in reduced burial depth and soil resistance near the pipeline touchdown point. Additionally， changes in laying angles affect the pipeline's bending moment and soil resistance. These findings provide valuable theoretical support and references for the practical application of the J-lay laying technique in deepwater engineering.

Key words: deep-sea pipeline laying, J-lay, nonlinear seabed, numerical analysis