Abstract: Aiming at the existing technical defects of DC boost converter in clean energy grid-connected power generation system, this paper proposed a novel high step-up quasi-Z-source DC-DC converter. By combining the quasi-Z-source network with a unique coupled inductor integrated structure, the proposed converter can achieve high voltage gain at small duty cycle and turns ratio. The clamp circuit utilized in the topology can recover the energy stored in the leakage inductor and effectively suppress the voltage spike caused by the leakage inductor. In addition, the voltage stress of the power components is low, therefore low rating devices can be used to improve the conversion efficiency. Continuity of input current and common ground between input source and output load make the converter more suitable for renewable energy applications. The operation principle is analyzed, and critical formulas and design are presented. Then the performance comparison with other converters is discussed. Finally, a 200 W rated power prototype was designed and established for experimental verification, and the experimental results match the theoretical analysis.