The invention provides a lubricating grease composition. The lubricating grease composition is prepared from the following components in parts by mass: 6 percent to 10 percent of compound soap, 70 percent to 80 percent of polyalpha-olefin, 0.2 percent to 1 percent of an antioxidant, 1 percent to 3 percent of an extreme pressure anti-wear additive, 0.2 percent to 1 percent of an anticorrosive agentand 10 percent to 20 percent of a solid lubricant, wherein the solid lubricant comprises one or two of compound polytetrafluoroethylene (PTFE) micro-powder, PTFE micro-powder and melamine cyanurate;the compound PTFE micro-powder is polyphenyl ester PTFE compound micro-powder. According to the lubricating grease composition provided by the invention, a compound PTFE micro-powder material is added, so that the lubricating grease composition can be used in a temperature range from -40 DEG C to 150 DEG C and has excellent anti-wear performance; the lubricating grease composition is suitable forlubricating a high-stress sliding friction pair or a rolling and sliding combined friction pair and is especially suitable for lubricating an automobile seat angle adjuster and a worm rack part of a steering gear. The invention further provides a preparation method of the lubricating grease composition.