The invention discloses a protective cover for an outdoor distribution box. The protective cover is of a herringbone-top structure; the surface of the protective cover is made of tent cloth; symmetrical support rods are arranged on two sides of the protective cover; a hook is arranged at the tail end of each support rod; a position clamping block is arranged between the two support rods and is of a pyramid trustum structure; grooves are formed in the side surfaces of the position clamping block; the support rods and the side surfaces of the position clamp blocks are clamped through the grooves; and the side surfaces of the position clamp blocks are slopes. The protective cover is simple in structure and convenient to mount, can shield sun and keep off rain, has a good protective effect and is safe, reliable and environment-friendly.