The invention discloses a transmission line malfunction positioning method based on non-contact magnetic measurement. The method is characterized by comprising step A, confirming a malfunction section; step B, identifying the type of the malfunction; and step C, internally positioning the malfunction section, wherein the malfunction section is confirmed by the following ways: constructing a remote terminal arranged on a transmission steel pylon, wherein the remote terminal consists of a microprocessor CPU (Central Processing Unit), a sensor, a signal regulating module, a data acquisition module DAQ (Data Acquisition), a storing module, a data communication module and a power supply module, wherein the sensor is used for measuring the three-dimensional component of the magnetic field at a three-dimensional space, and the data is transmitted to the DAQ module after passing through the signal regulating module. The invention provides a new transmission line malfunction positioning method based on the non-contact magnetic measurement. The malfunction section is positioned according to the magnetic data near the transmission line measured by a magneto-resistance magnetic field sensor with high sensibility, high band width and low cost.