Suction anchors are widely used as a foundation type in deepwater environments. Unlike homogeneous soil, the mechanical penetration characteristics of suction anchors in layered soils are extremely complex, influenced by the variation in soil properties and interfaces between layers. Therefore, it is necessary to study the mechanical behavior of suction anchors during penetration in layered soils. An Euler-Lagrange coupling method was used to simulate the penetration process of suction anchors, and numerical simulations were validated through model tests. The mechanical penetration characteristics of suction anchors in layered soils were analyzed. The results show that, influenced by the mechanical properties of layered soils, vertical stress gradually increases during penetration, forming a vertical stress arch at the anchor tip. The stronger the soil strength, the more concentrated the vertical stress. Additionally, when a suction anchor penetrates from silty clay into silty clay, the mechanical properties of the soil change, causing the side friction and end resistance to increase rapidly. This study, which combines experimental and numerical methods, investigates the mechanical behavior of suction anchors during penetration in layered soils and provides valuable references for deep-water suction anchor penetration in layered soils, offering significant engineering practical value.