Mixed modeling method with underwater electric potential as a clue is put forward in order to research the distribution characteristics of corrosion related static electric and magnetic fields of a ship,that is to regard a ship as a combination of horizontal current line and several discrete dipoles.The unknown parameters of the mixed model can be found out by fitting the measuring data of the underwater electric potential in a plane under the ship.Then the characteristics of corrosion related static electric and magnetic fields underwater can be studied based on the mixed model.The ocean environment has been simulated in laboratory,then the method of mixed modeling has been validated by experiments using a 1∶100 physical scale model of a ship,then the distribution of corrosion related static electric and magnetic fields of the ship model has been calculated based on the built mixed model.The experimental results show that the mixed modeling has advantages of less unknown parameters,easier actual measurement,less calculation and more stabilization.