The laser power source is one of the key equipments of the power supply module (PSM), which is crucial to transmit the energy efficiently with high stability and reliability. Therefore, it is important to measure the pulse current quickly with high reliability and accuracy. A novel opto-electronic current transducer (OECT) based on Rogowski coil is demonstrated to measure high-power high- voltage laser source. The CT is placed in the high-voltage side and is used to measure different durations of pulse current with large amplitude for the laser power source. Models with lumped parameters and dynamitic properties of the Rogowski coil with a new type of integrator have been analyzed in detail. The optimizing parameters of the transducer have been introduced. Measurement results of the opto-electronic current measurement instrument are described respectively. The simple sensor geometry gives high accuracy and sensitivity, wide dynamic range, and immunity from slow- variance temperature.