In this paper, a simplified magnetic localization method and system for indoor robot was proposed. A transmitter coil and a set of three axis receiver coils were ranged in the localization space to form the magnetic coupling system. The Cartesian coordinate system was built according to the three-axis orthogonal receiving coils. A magnetic field was setup by the transmitter coil which was activated by a sinusoidal current signal. The 3-axis receiver coils sensed the change of the magnetic signal around, and their intensities could be calculated to extract the characteristic parameters for computing the position of the transmitter coil. Here, the transmitting coil was fixed on the mobile robot, while the 3-axis receiver coil was located in a certain position of the building. The characteristic parameters could be calculated based on the magnetic dipole model. According to the simulation and experimental results, this method proves to have high efficiency and satisfactory accuracy which are suitable for mobile robot localization.