Abstract: When oil is transported through pipelines, electrostatic safety accidents may be caused by the static electricity of oil flow in pipelines. In order to solve this problem, the design idea and implementation scheme of pipeline oil-flow charge density monitoring and interlocking control system were proposed. The principle of detecting oil-flow electrostatic charge density by measuring the central potential in the oil pipeline was studied. Oil product charge density gauge was designed and developed on the basis of rod ball sensor. This gauge, together with oil-spill electrostatic protector, constitutes the pipeline oil flow electrostatic monitoring and interlocking control system. And this system was, for the first time, used on site for the monitoring and interlocking control of oil-flow electrostatic charge density in the process of oil loading at an oil depot in China. It is shown that testing data can reflect the static electrification situations while the oil is loaded onto tank trucks and this technology improves the oil-flow electrostatic monitoring capacity effectively. If this technology is used for oil transportation process control, the safety of oil production transportation can be guaranteed.