The invention discloses a seton for complex anal fistula. The seton comprises a seton main body, wherein the seton main body is of an integrally-molded structure, the seton main body is made from a silica gel and a rubber material, and during an actual use process, the middle part of the seton main body is a middle part of running along a fistula; two ends of the seton are free extension ends which are exposed out of the skin, the outer circle surface of the middle part is convexly provided with multiple convex particles, and a fur brush structure is formed by virtue of the multiple convex particles. The seton for complex anal fistula has the advantages of thorough draining, low residual possibility and the like.