In order to reflect the control characteristics of a spacecraft under the interaction between many disciplines,a multi-domain modeling and simulation platform,dealing with mechanics,electricity,control,software,et al.is developed.This platform is composed of the following modules: the attitude control software,the flywheel system(including motor and its driver,bearing friction,the mechanism of the flywheel et al.),magnetotorquers,attitude sensors,attitude dynamic,orbital dynamic and environment torques,and so on.All the modules are realized using Modelica language,and integrated into an organic whole.The simulation of two typical attitude control modes—attitude established and attitude manoeuvre shows that,this simulation platform is not only used to analyze the control performance of the closed-loop system,but also to evaluate the effect of each domain’s devices.Sufficient application of this platform during all the phases(project proposal,subsystem,system,et al.) can attain the purpose of Multidisciplinary Design Optimization.