Abstract: Measurements of the properties of lightning currents are important for the analysis of lightning accidents and the study of lightning protection. In this paper, a lightning current measurement system based on a signal-energy dual acquisition coil was proposed to address the high hardware requirements and difficult energy supply of the Rogowski coil systems. Based on electromagnetic theory, the relationships of the coil parameters on the frequency band and output characteristics were derived, and the signal coil was designed to fit the amplitude and frequency characteristics of the lightning current. A passive peak holding circuit was designed, which allowed the acquisition voltage of the signal coil to maintain values above 90% of the peak for 60 ms, reducing the sampling rate requirement of the acquisition device. Based on the charge and energy conservation relations during the lightning current energy harvesting, the energy harvesting coils and circuits are designed to meet the self-supplying energy demand. The working time of each module is properly allocated and self-triggered measurements and energy obtaining of the system under lightning current conditions are achieved. With the impulse current experiment, it is verified that the system can measure the amplitude and polarity data of the lightning current and store them in the power-off state. The system can supply 50 mW of energy for 1s at 10 kA of lightning current, with a measurement error of less than 5% for the lightning current amplitude.