Simulation is the main method of unmanned helicopter control technology and its application research. According to the state coefficient matrix and control coefficient matrix obtained under different speeds, heights and weights by wind tunnel test, a method based on multi-dimension linear interpolation is proposed to set up unmanned helicopter non-linear model. Then Augmentation controller is designed based on the non-linear model, and simulation is made in VC++ software development environment. The phenomenon of longitudinal and lateral channels and height fall during forward flight are reproduced, and the reasons are analyzed in detail. In the flight simulation software, modularized controller design is used in flight model which has generality.