This paper presents a low voltage stress Boost converter which can be applied to photovoltaic system.Because of the switch of the traditional Zsource Boost converter connected with load directly with high voltage stress,the proposed converter isolations switch element and load by coupled inductor,the voltage stress of the switching element reduced effectively.The new converter not only retains the advantages of the original Zsource network, but also can obtain higher voltage gain by adjusting the ratio of the coupled inductor at the same duty cycle. The operation process of the proposed topology is analyzed, and the feasibility of the proposed topology is verified by simulation.