Abstract: The flexible solar array (FSA) of a space station has the following kinds of prestresses: (1) the thermal stress caused by periodically varying temperature field in the central truss; (2) the deployment stress in the oblique rod of the central truss; (3) pretension in the flexible solar blanket. These kinds of prestresses will affect the geometric stiffness and change the dynamic characteristics of the FSA. The Abaqus nonlinear dynamic solver is used in this paper. First of all, the central truss and the flexible solar blankets are modeled separately to analyze the effect of the prestress. Results show that the pretension in the flexible solar blanket plays a major role in affecting the dynamic characteristics. Then, the whole model of the FSA is built to analyze its dynamic characteristics in consideration of the pretension. Finally, a comparison is made between the results with and without the prestress.