The invention provides a DC microgrid photovoltaic-wind energy system configuration optimizing method taking into account cost and reliability. The method includes steps of calculating cost (i) Cost and acquiring reliability A; solving A, A, P and Psi through minimization formula Cost and maximization formula DNM. Compared with a single-target optimization method, the method provided by the invention can obtain a more optimized configuration structure when taking into account equipment cost and energy acquisition reliability and is suitable for a grid connected mode and an isletmode.