Abstract: Carbon quantum dots have excellent optical properties and have important applications in the field of environment and energy. In this paper, the pulsed liquid phase discharge technology was used to generate plasma in the mixed aqueous solution of citric acid, urea or melamine, which triggered chemical reactions to synthesize carbon quantum dots (CQDs). The optimal conditions for preparing CQDs were obtained through the optimization of parameters such as discharge voltage and discharge time, etc., and the morphology, structure and fluorescent properties of the obtained CQDs were characterized. The results show that the optimal conditions for synthesizing CQDs are as follows: a pulsed discharge peak voltage of 25 kV, an electrode spacing of 5 mm, and a discharge time of 10 min, and the luminescent properties of CQDs can be adjusted by discharge parameters and material ratios. The result of this paper shows that the liquid discharge plasma method is an effective method for rapid synthesis of CQDs. On the one hand, it provides a reference for the rapid synthesis of CQDs; on the other hand, it further broadens the application scope of liquid-phase pulsed plasma technology.