Automatically Guided Vehicle System(AGVS) is the key facility in flexible integrated production and materialflow automation of the AGVS working performances. In the study of AGVS, a very important premise is how to establish the mathematical model of steering system, and based on this model to establish the controlling model. Because of the complexity of modern industrial plant, it is very difficult to do so by pure theoretical analysis method. From the viewpoint of control, it is hoped to find a kind of mathematical model, which can not only properly reflect system motion law, but also has a low order. With the development of the system identification theory and method, choosing a proper identification algorithm satisfying the different aims, circumstances,plants, etc. will be a kind of good approach for solving the above questions. By analyzing the experimental input and output data, the Generalized Least Square(GLS) algorithm was chosen and the system differential equation was obtained. It was proved that it is a good method to solve the questions on modeling and controlling of complicated industrial plant .