Topography has a great influence on the inversion and interpretation of magnetic anomaly, especially where the abnormal body is distributed close to the ground.In order to reduce this influence, the authors deduced limited-deep two-dimensional thick plate forward formula under the rugged topography, and put forward a new method to divide the underground objects under the rugged topography.In addition, focusing inversion has good focusing effect for physical property;if we can predict that the magnetic anomaly is caused by ferromagnetic body, then focusing inversion can be applied to obtain better situation.It is obvious that this method is suitable for the inversion of ferromagnetic body.The authors combined two-dimensional magnetic anomaly forwarding and focusing inversion under the rugged topography, and carried out corresponding model test, then compared this method with focusing inversion under the flat topography with max smoothness inversion under the rugged topography, and the results show the effectiveness of the method put forward by the authors.Finally, the authors applied the method to magnetic anomaly profile obtained from Tex, Xinjiang, and made a reasonable explanation for the ferromagnetic body.