The work aims to improve extreme pressure properties of lubricating greases by optimizing compound proportion of different additives. Three kinds of additives, antimony dialkyldithiocarbamate (SbDTC), zinc dialkyldithiophosphate (ZDDP), sulfurized isobutylene (SE), were used to form 10 formulas in different proportions in the method of three component simplex-centroid design. Extreme pressure property and adaptability of different additive formulas in three base greases were evaluated using Timken wear tester, so as to select the formula with extreme pressure synergistic effect, and elemental chemical state and depth distribution on worn surface reaction film were analyzed using X-ray photoelectron spectroscopy (XPS). Extreme pressure properties of the three base greases could be improved by formula 1—7 to varying degrees, lithium-based greases (N-Li) exhibited better adaptability in naphthenic-based oil. Formula 5 (SbDTC and SE compounded in equal proportion) exhibited the best extreme pressure property in base greases with Timken OK load of 315 N, film thickness measured by XPS of 20~30 nm and higher content of Sb and S in the reaction film. Formula 6 (ZDDP and SE compounded in equal proportion) exhibited the worst extreme pressure in base greases with 135 N Timken OK load of below 135 N, and it showed counteraction. For formula 8—10, when compound ratio of the three constituents was changed, the formulas varied a lot in extreme pressure properties. The higher the proportion of SbDTC concentration was, the more obvious the effect on improving grease extreme pressure properties. the compound ratio of the 3 additives has a great influence on its extreme pressure properties, SbDTC exhibits favorable extreme pressure synergistic properties when being mixed with SE and ZDDP in equal proportion. The extreme pressure properties of the additives are related to thickness of the lubricating film formed on the wear surface and content of active elements, especially Sb and S content on the surface.