The pipeline cathodic protection monitoring was used in potential test of cathodic protection in pipeline. The test period was last 1 or 2 months or longer. the measurement accuracy and reliability of testing data are affected by testing environment and the accuracy of the instrument in some ways, so in order to meet the requirement of cathodic protection potential monitoring, it is necessary to design a cathodic protection potential acquisition system to realize the automatic monitoring of cathodic protection potential, the system was an automatic acquisition pipeline potential device used in buried steel pipeline environment. The internal circuits of the device used single chip design of low power consumption and are high precision DC voltage and AC voltage effective value measurement device all based on AVR MCU, combining hardware with software, the results show that the system realizes the automatic acquisition of buried pipeline potential and completes the indicators in China.