Pile group foundations with elevated piles will be one of the most popular foundation types on soft clay for offshore wind turbines in the next few years in China. The calculation of complex load, the analysis on foundations’ mechanical behaviors and deformation mechanisms, as well as the determination of foundation bearing capacity under complex load are the key problems that should be solved urgently for the design of pile group foundations of offshore wind turbine. Aimed to the common deep soft clay in the offshore area in China, the most unfavorable typical load combination for pile group foundations of offshore wind turbine was analyzed. By using new hyperbolic p－y curve model of pile foundation in soft clay, t－z curve model and q－z curve model in API code, an internal force and deformation analytical model on elevated piles was established under three-direction complex load. Then, optimization analysis on the main parameters, i.e. embedment and diameter of pile, circle diameter of pile cap and inclination of pile, was investigated. The results show that the effect of pile length on internal force and deformation of pile group is not significant but it is benefit to increase the inclination of pile when the pile’ uplift resistance and compression capacity meet the requirements; though the influence of pile group’s circle diameter increase on pile deformation controlling is little, it can effectively reduce the pile axial force.