Based on the theory of multi-system kinematics,each structure error of the two-axis optic-electrical turntable was analyzed,and the topology structure of the turntable was obtained.Error model of turntable structure was established,the formula of turntable composition error including every structure error was derived.The turntable errors were numerically simulated by Mathematica software,and the influence of different structure errors on the pointing accuracy of the turntable was analyzed,which lays a foundation for distributing,designing,separating and measuring of turntable errors.