This study aims to design a novel experimental system for replicating the bearing capacity behavior of layered seabed foundations during the process of leg piling and penetration. A test apparatus for a jack-up offshore platform was developed, with a telescopic pile foundation hydraulic cylinder mounted at the base of platform leg to achieve experimental investigation of penetration behavior through layered seabed soils. A servo-hydraulic system model was developed by incorporating the Proportional-Integral-Derivative (PID) control algorithm into the proportional valve control system, thereby realizing dynamic simulation of various penetration depths and soil bearing capacities through precise hydraulic cylinder pressure regulation. A series of simulation analyses and experimental tests were conducted to delve into the variation in bearing capacity during the piling process, with a focus on the influence of soil shear strength, layer thickness, and backfill characteristics. The findings indicate that the experimental system exhibits a high level of accuracy in simulating the bearing capacity of complex layered seabed foundations, with an overall error maintained within 15 %. This study provides an experimental methodology and technical approach for simulating the process of pile leg penetration in the investigation targeting the structural integrity and stability of offshore platforms.