A thermo-mechanically coupled numerical model was developed to analyze the processes of stationary shoulder friction stir welded (SSFSW) AA6061–T6 aluminum alloy plate with a thickness of 12mm based on the Deform-3D software. The effects of welding parameters on the temperature distribution

welding thermal cycling and bearing status of the tool in the welded joint were investigated. It was found that the 50% increase in rotational speed will cause the peak temperature of the nugget to increase more than 21.6%

and the 50% increase in welding speed will cause the high-temperature residence time and cooling time to decrease more than 50% and 60%

respectively. For given rotating speed in the range of 1000r/min to 1500r/min and welding speed in the range of 100mm/min to 150mm/min

the axial force of SSFSW is in the range of 28.2kN to 24.3kN and the forward resistance is in the range of 17.4kN to15.3kN; The maximum torque of tool pin is in the range of 27.3N·m to 25N·m. The 50% increase in rotating speed will reduce 13.8% axial force

the 50% increase in welding speed will increase 13.7% forward resistance. These numerical results mentioned above provide the important theoretical basis for the tool design and welding parameters optimum of SSFSW for aluminum alloy thick-plate.