The nanosecond high power laser emission system has an important impact on the detection performance of LIDAR.In this paper,the commonly used low side gate drive is modified to obtain a high side gate drive method,making it suitable for common cathode laser emission circuits.And the high side drive method utilizes a half bridge driver with two GaNFETs as core devices to control the light emission of the laser diode.The effects of voltage,capacitance,resistance,and inductance on the current waveform flowing through the laser are analyzed in this topology.After experimental testing,the circuit is capable of generating a pulse width of 3.1 ns and a peak power of approximately 65 W at high repetition rates,which can be used as a transmitter module for LIDAR to scan and image scenes.