Abstract: In order to debug and verify this underwater navigation system,the simulation platform of navigation system for underwater vehicle is developed.Overall architecture of the simulation platform is proposed.The methematical models and simulation algorithm of vehicle module,inertial navigation system module and gravity measurement module are described.The gravity matching algorithm is introduced too.Finally,the simulation platform is verified and analyzed through system simulation.The results show that the architecture of the platform is reasonable and reliable;and the mathematical models and simulation algorithms of sub-systems are also valid and practicable.