Oil and gas pipelines must be cleaned regularly to ensure their normal operation. It is significant to track the pig when it’s working in the pipeline. With the GPS and GSM technology, this paper introduces a kind of intelligent pig tracking system, The system uses ultra-low frequency electromagnetic wave with strong penetrating to transmit data. It concludes two parts: transmitter part and receiving part. The transmitter part which connects with the pig is controlled by SCM, interval transmitting ultra-low frequency pulse signal. The receiving part uses AVR SCM as its core controller and is mainly composed of magnetic pulse signal receiving module, GSM module, GPS module and LCD module. When the pig is working, the transmitting part interval transmits ultra-low frequency pulse signal. After receiving the right signal, the receiving part will send the location information to the designated GSM handsets. This system makes pig remote monitoring come true.