In order to improve the accuracy

a new magnetic direction finding system is designed through adopting high precise stepper motor.The system only needs one GMR magnetic sensor’s output.The magnetic sensor rotates with the stepper motor in the horizon plane.Through calculating the position of maximum output

the magnetic bearing can be determined.Considering about the influence of interference and test noise

hybrid data processing method based on genetic algorithm and optimization theory is researched.Through fitting the four parameters of the sine wave to the test signal

the initial phase is obtained and then improves the accuracy.Simulation research and engineering experiment prove that the direction finding method is well accurate and stable.