The invention relates to a method for preventing rust and reducing grounding resistivity for a lightning protection grounding body, which mainly solves the problems of singleness in rust-resistant plating metal protection materials, poor rust-resistant performance, short service life, instability in grounding resistivity, high potential safety hazards, high weight, breakability, difficulty in carrying and mounting and occupation of the ground. The surface of the steel grounding body is plated with nickel after being plated with copper, the rust resistance of the grounding body is superior to that of an existing grounding body singly subjected to copper or nickel plating anti-corrosion process, the service life of the grounding body can be up to 30 years, and the grounding resistivity is stable, safe and reliable. High-carbon flexible conductive graphite wire jackets are high in ductility, free of being pulverized or smashed and low in electric resistivity, the conductive direction can be changed into longitudinal conductive direction by means of extrusion, reactance is overcome, electric resistivity is low, current can be dispersed fast, and simultaneously, the grounding body is combined firmly with resistivity-reducing plaster film attached on the surface thereof during reduction of electric resistivity. The resistivity-reducing plaster film composited by coating level polyving alcohol glue and high-carbon graphite phosphorus powder has the advantages that the resistivity-reducing plaster film is solid before being mounted, stick-proof and easy to transport, carry and mount and after being mounted, can expand by 20 times when absorbing moisture, and thereby, water and soil can be combined excellently and lightning flowing to the ground can be released quickly.