A novel single-switch high-gain converter with no transformers and no coupled inductors is studied in this paper. Since the voltage lifting unit is added to the Boost converter, the voltage gain of the converter is improved, the voltage stresses of the switch and diodes are reduced, and the conduction loss of the switch is reduced under the condition of a small duty cycle. As a result, the efficiency of the converter is improved. To further improve the dynamic performance and anti-disturbance capability of the converter, the immune feedback mechanism is introduced based on the analysis of a single neuron controller. A fuzzy immune-single neuron PID control strategy is studied in this paper, in which the fuzzy immune control is combined with the single neuron smart controller to realize self-tuning of the single neuron proportional coefficient. Finally, a simulation study of the proposed converter and control strategy was carried out, and an prototype with an output of 200 V/0.5 A was designed for experimental verification. Both the simulation and experimental results show that the proposed converter can obtain a higher voltage gain under a smaller duty cycle. Compared with the traditional PID control strategy, the proposed fuzzy immune-single neuron PID control strategy can more effectively suppress system disturbances and improve the dynamic performance of the converter, indicating a stronger adaptive capability and a stronger robustness.