Abstract: To locate Pipeline PIG and retrieve the lost PIG, a portable pipeline PIG localization system appliance based on extremely low frequency(ELF) electromagnetic field was developed. Based on the characteristics of the magnetic dipole magnetic field distribution and the propagation of ELF electromagnetic field, an emitter, a portable receiver and a data acquisition module were developed, and a LCD display module was used to display the change of the amplitude of the received ELF electromagnetic field to help to locate the PIG. The localization appliance was tested and good results were achieved. The appliance was convenient to use and flexible to accommodate different situation, and can accurately locate the PIG, and would bring great significance to the maintenance work of the pipeline.