In a wide range of visual simulation battlefield environment, the motion state of simulation entities are complicated and changeable. In order to solve this visual simulation of fidelity problems, this paper analyzes the geometry correspondence relationship between the observer and the target, gives three control modes: equidistant mode, uniform speed mode, uniform acceleration mode, the basic algorithm of observer controlling in virtual scene is designed. Under the MFC framework, applying of Vega API function achieves the C language calling Vega visual simulation platform, achieving the observer servo control method for the target, solving the problem of observer automatic controlling in visual simulation system. In the visual simulation experiments, a flexible controlling to viewpoint way is achieved, with a strong practical intuitive property, while enhancing the realism and interactivity of viewpoints.