The invention discloses a slope roof lightning conductor mounting method. The method comprises the following steps: integrally pouring a lightning conductor foundation at a center position of a slope roof structure, then producing a lightning conductor base and a lightning conductor welded thereon, connecting the base and the lightning conductor base in a threading manner, wherein the lightning conductor comprises an upper section and a lower section of a lightning conductor rod which are welded together by virtue of a spherical connecting way, the top of the upper section is provided with an early-discharging lightning conductor head, and reinforcing ribbed plates which are fixedly connected with the lightning conductor base are uniformly welded on the periphery of the lower section in a separating manner; and welding two grounding leads connected with a ground grounding net on the lightning conductor base. By adopting the slope roof lightning conductor mounting method, the conventional structure which needs to be simultaneously provided with a ground lightning conductor and a roof lightning conductor can be changed, the lightning conductor is only arranged on the roof, and the lightning conductor is connected with a grounding system, so that the integral structure is simple and convenient to install, the construction period is short, the investment cost is low, and the lightning effect is significant.