The invention discloses a double-Cuk buck-boost output parallel-type converter which is formed by connecting two Cuk-type DC / DC (direct current / direct current) converters capable of achieving the buck-boost output at the output in parallel, and can achieve the DC / AC (direct current / alternating current) single-phase conversion and further achieve the three-phase conversion through expansion. The converter has the following basic functions: the double-Cuk buck-boost output parallel-type converter can achieve the buck-boost conversion and normally serve the function of conversion even if the inputted DC voltage is lower or the variation range of the DC voltage is wider; the problem that the bridge arms are directly connected is avoided in the entire circuit, thus ensuring the high reliability; the follow current is not allowed to pass through the body diode of a switching tube, but flows through an independent diode, so that a power switching tube and a power diode can be respectively subject to optimized design; the design of circuit parameters, which is based on the method for designing a DC Cuk converter, is simple; and the inductive current runs in a continuous state, thus reducing the EMI (electro-magnetic interference). The invention is mainly applicable to the fields of photovoltaic generation, fuel-cell power generation and other power generation based on renewable energy and new energy, in which the level of operating voltage is lower or the variation range thereof is wider.