The invention provides a research system for liquid light induced breakdown and a cavitation effect. Laser lights emitted by a pumping source module and a detection source module are subjected to beam combination through a dichroscope A; a 50% spectroscope, a 40x objective lens, a sample cell, a dichroscope, a focusing lens and a photoelectric detector are arranged in sequence in a direction of the principal optical axis of the dichroscope A; a laser energy power meter is arranged in a vertical direction of the 50% spectroscope; objective lenses are clung to three walls of the sample cell, wherein a 10x objective lens is connected with a high-speed camera, and a vertical LED light source is arranged on another wall of the sample cell; the photoelectric detector is connected with a oscilloscope. The research system provided by the invention can realize nanosecond laser induced liquid light induced breakdown, image information of cavitation bubbles formed during breakdown is monitored in real time, and information of laser energy is recorded at the same time; the research system provides a direct theoretical direction and a practical support for selecting a laser dosage and a mode of action and estimating an action effect during laser medical treatment.