The low load-bearing capacity, reduced abrasion resistance, and sedimentation susceptibility of poly(tetrafluoroethylene) (PTFE) have severely limited its use as a lubricant additive. Herein, one-step preparation of nanocomposite materials as lubricant additives with superior tribological performance is achieved by combining PTFE with hydroxy-silicate magnesium (MSH). The findings indicate that the composite powders consist of in situ-formed MSH on the surface of spherical PTFE. There is a low level of corrosion in the composite powder, and it is highly dispersed in the lubricating lubricant. Additionally, adding 1.0 wt % nanopowders to PAO-6 results in a significant reduction of 22.8% in the coefficient of friction of the lubricating oil. Concurrently, the friction pair’s attrition volume has been reduced by 76.1%. The maximum nonseizure load (Pb) of the lubricating oil has also been increased from 600 to 1300 N. The outstanding performance can be attributed to the combination of the superior antifriction properties of PTFE and the ability of MSH to increase the surface strength of the friction pair.