The invention relates to a high-gain soft-switching DC converter and a control method thereof. The high-gain soft-switching DC converter includes a DC input power supply, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first diode, a second diode, and a third diode Tube, first inductor, second inductor, first capacitor, second capacitor, third capacitor, fourth capacitor, coupling inductor and load. Through the control of the four switching tubes, the high-gain soft-switching DC converter of the present invention has the advantages of high voltage gain, low input current ripple, high conversion efficiency, and small voltage stress of switching devices, and all four switching tubes can realize Zero-voltage soft switching, very suitable for non-isolated renewable energy power generation systems.