Abstract：The method for Curie interface depth inversion using OT anomaly includes two steps:（1)△丁anomaly that results from Curie interface undulation is separated out from total anomaly by using mufti-interpolation cutting method，and (2) inversion of OT anomaly is made to obtain Curie interface depth by taking spline function method for nonlinear inversion of 2-D single magnetic interface depth.Spline function method for nonlinear inversion of 2-D single magnetic interface depth is suitable to the case where residual magnetism and induced magnetism have different directions respectively. The optimal inversion interval can be determined by doing an amplitude spectrum analysis of aT anomaly. Nonlinear inversion is better than linear inversion. Iteration is monotonously convergent. Inversion result only has some errors when datum interface depth is inaccurate.
