The invention relates to a compound grease additive, which is characterized by including graphite, a base oil, a dispersing agent, a thickening agent and an extreme pressure antiwear additive, and the composition of the raw materials by weight percentage is as follows: 20 to 50 percent of the graphite, 1 to 10 percent of the dispersing agent, 5 to 10 percent of the thickening agent, 10 to 30 percent of the extreme pressure antiwear additive, and the residue is base oil; the sum of the component percentage of all the raw materials is equal to 100 percent. The compound grease additive of the invention has low cost, can obviously enhance the functionalities of abrasion resistance and ultimate working capacity, etc., obviously reduce the usage amount of the grease, prolong the service cycle of the grease, and is environment-friendly.