It is very important to determine the magnetic object location using the magnetic anomaly. This paper presents a method for determined the magnetic object location using the geomagnetic field intensity. The magnetic object center position can be obtained by the amplitude of the analytic signal( AS) of geomagnetic total intensity. The vertical distance can be obtained by the value of magnetic anomaly on center position. But the vertical distance from measuring plane to magnetic object is not relatively precious because of not eliminating the geomagnetic normal field in the calculation process. The method of modeling geomagnetic normal field in small space is proposed based on Taylor polynomial. The impact of geomagnetic variation field for the precious of model is analyzed. Through the measured data and the model data,total intensity magnetic anomaly on the measuring plane is obtained which is used for calculating the vertical distance of magnetic object by calculating model. The experimental tests have been conducted on open field on the campus of Harbin Engineering University. The results show that the calculated results and real values match perfectly using this method. This paper presents a method for determining the magnetic object position using the magnetic anomaly. The magnetic object center position can be obtained by the amplitude of the analytic signal (AS) of geomagnetic total intensity. The vertical distance can be obtained by the value of magnetic anomaly on center position. But the vertical distance from measuring plane to magnetic object is not relatively precious because of not eliminating the geomagnetic normal field in the calculation process. of modeling geomagnetic normal field in small space is proposed based on Taylor polynomial. The impact of geomagnetic variation field for the precious of model is analyzed. Through the measured data and the model data, total intensity magnetic anomaly on the measuring plane is obtained which is used for calculating the vertical distance of magnetic object by calculating model. The experi mental tests have been conducted on open field on the campus of Harbin Engineering University. The results show that the calculated results and real values ​​match perfectly using this method.