The invention, which belongs to the technical field of the electromagnetic wave and microwave, provides a double-passband design method based on a multi-screen frequency selection surface. The invention relates to a double-passband design method based on a multi-screen frequency selection surface, thereby realizing the filter characteristic of the double-passband frequency. According to the designmethod, a three-screen FSS and two dielectric substrates arranged in parallel are employed, wherein the three-screen FSS is parallel to the dielectric substrates and is arranged symmetrically relative to the dielectric substrates. A frequency selection surface unit structure is formed in a square arrangement manner and is formed by an upper surface metal layer, an upper dielectric layer, an intermediate metal layer, a lower dielectric layer and a lower surface metal layer that are arranged successively from top to bottom. On the basis of the three-FSS-cascaded symmetric structure, the miniaturization degree of the structure is improved by a U-shaped rotary symmetric unit; the flexibility of the design is enhanced; the space of the two bands is easy to adjust; and the double-passband frequency characteristic having the two-order filter characteristic is realized. Moreover, the structure is simple; the method is easy to realize; the passband losses are low; the bandwidth is increased; and the steep cut-off performance is good.