Abstract: The satellite dynamics during solar array deployment is studied with the digital simulation method. After a comparison made between different methods available for dynamic analysis the D'Alembert's principle in Lagrange's form is used to derive the mathematical model governing the satellite dynamics. The satellite dynamics during solar array deployment is then digitally simulated for various deployment conditions, including symmetric and antisymmetric array deployment, non-synchronous release of the right and left array, different spring rigidities and array positions. Some useful conclusions are obtained after the simulation.