A 3D elastic-plastic and coupled thermo-mechanical FE model for friction stir welding(FSW) of aluminum 7075 plate with conical pin was developed based on the dynamic explicit code ABAQUS/explicit. Then temperature distribution and deformation behavior of 7075 aluminum alloy plate in FSW process were simulated and analyzed. The results show that the temperature is distributed in the plate with an approximate ellipse shape and decreases from the edge of the tool shoulder to the outer side of the plate. Furthermore, the maximum temperature zone decreases gradually from tool shoulder to the bottom of the plate. In the welding zone, the equivalent strain is also distributed with ring shapes, and it decreases from the edge of the tool shoulder to the outer side of the plate.