Currently, there are a series of problems such as insufficient power, short range, and low operating efficiency of commercially available electric microtillers in mountainous and hilly areas, and this paper proposes a three-port power converter design for electric microtillers based on a hybrid energy storage system. The design adopts a hybrid energy storage structure of lithium batteries and supercapacitors, a dual closed-loop controller and a three-port power converter, which ensures the voltage stability of the system during load fluctuations. To further reduce the cost of tillage, a combination of photovoltaic power generation and three-port power converter is used to realize the efficient management of energy flow between the photovoltaic module, energy storage module, and motor. During the tillage process, the three-port power converter can provide feedback adjustment for different depths and changes in soil hardness based on field test data. Through simulation and experiment, the high efficiency and stability of the three-port power converter and its application feasibility and application prospect are verified.