Objective At present, there are more and more domestic brands of ultrasonic scalpel, but there is very little literature on the development of ultrasonic scalpel energy generator and parameter optimization. This research aims to develop a novel ultrasonic scalpel energy generator, which is used for research on different control modes and different parameter adjustments. Methods The hardware of the ultrasonic scalpel energy generator is designed independently, and the Direct Digital Synthesizer (DDS) is composed of FPGA+DAC to achieve frequency adjustment. Class E switch power amplifier is used to reduce system heating; In the algorithm design, the small step frequency tracking strategy is adopted to make the system work in the resonant state,and the PID algorithm realizes constant current and constant power output; Finally, the performance test experiment was carried out. Results The minimum step size of DDS frequency adjustment is 0.0116Hz, and the frequency tracking keeps stable during the cutting process; The constant current output makes the ultrasonic scalpel have good cutting performance under no-load and loaded conditions. The current fluctuation is less than 1mA during the working process, and the cutting speed is significantly accelerated with the increase of the current. Under the load state, the time of cutting small intestine in 300mA constant current mode is (8.01 ± 0.35) s,and the thermal damage width is (3.57 ± 0.23) mm. Conclusion The ultrasonic scalpel energy generator designed in this scheme can achieve high-precision frequency tracking and stable constant current output. This set of equipment provides a feasible scheme for the design of ultrasonic scalpel energy generator.