The current modeling and measurement of ships’ magnetic field are mostly established when the ship is under stationary conditions. In order to adapt to the real environment of ship under navigation，there is an urgent need for a calculation method suitable for the induced magnetic field generated by a moving ship. Through the analysis of test point and theoretical derivation，4 calculation methods of ship induced magnetic fields are introduced. Finally，these 4 calculation methods are analyzed by evaluating the maximum absolute error between the calculated value and the measured value. The results show that method 3 and 4 can be used to evaluate the error of the ship's magnetic field calculation results，and other unknowns of the induced magnetic field can be obtained by further calculation. Measurement and calculation tests show that it is recommended to use joint measurements in 4 major headings.
