Aiming at the high cost of the traditional liquid lens control system and the inability to meet the problems of personalised customisation, a control system for automatic focusing of liquid lenses is developed. The system selects ATmega32U4 microcontroller as the main control chip, LTC2662 chip and H-bridge circuit as the current output module for controlling the liquid lens to achieve zoom, and provides two operation modes, manual and automatic, for users to choose. The current output module of this system can output a stable working current of DC -300~300 mA, with an average error of 0.64% and a current stability of 0.327 7%; and the average time consumed by the auto-focusing of the focus control software is about 1.3 s, with an image resolution of up to 45.3 lp/mm. Compared with the existing liquid lens control system, this system realizes the automatic adjustment of the focus of the liquid lens, which is simple in operation, stable in performance, and low in cost. Compared with the existing liquid lens control system, this system can automatically adjust the focal length of the liquid lens with simple operation, stable performance and lower cost, providing more flexible and personalised customisation options for liquid lenses.