Based on the theory of transfer function method of distributed parameter system, a semi-analytic model of structural dynamic characteristics for solar array is established. In this model, the solar panel is divided into some strip elements, and the joint hinge on solar array is simplified as a uniform beam element, and the strip element and the beam element are combined by displacement continuum and force equilibrium at their common nodes. Numerical results of modal characteristics for single and composed panels of certain satellite solar array are presented, and these results are compared with those of finite element method.