Magnetic guidance drilling technology is use of magnetic guidance instrument measuring the distance between the signal source and the location of the instrument, and it is used to control the well trajectory to connect or parallel the target layer. And it is an effective supplement of the existing steering drilling technology. At present, the magnetic guidance drilling technology is mainly applied to drill horizontal wells in pairs for the super heavy recovery, CBM horizontal connected wells, underground soluble minerals, relief well and so on. This paper introduces the data processing and the related software development of the active magnetic measuring instrument.