Through the analysis of tilt angle concept, this paper puts forward a method for normalized vertical derivative using the characteristics of Inverse Hyperbolic Tangent function, with the purpose of detecting geological boundaries in potential field and extracting geological body distribution, characteristics of fracture structure and other geological information. Theoretical models and practical data processing show that the method can be an effective method for detecting geological boundaries with higher resolution and obtaining abundant geological information and is also of certain significance for detecting the geological boundaries, dividing tectonic units, and determining the fracture zone and the trend of geologic structure.