<p>Due to the inability of traditional hydrocarbon-based lubricants to withstand high operating temperatures, this study aims to synthesize silicone oils working as lubricants suitable for application in high-temperature environments. In this study, molecular structure design was utilized to incorporate three functional groups—phenyl, trifluoropropyl, and dodecyl—into the main chain of siloxanes, culminating in the successful preparation of multifunctional group-modified silicone oil (PMPFAS). The products were characterised by thermogravimetric analysis (TGA) to examine the impact of the functional group ratio on the thermal stability of the modified silicone oils. PMPFAS was then compounded with hydrocarbon base oil to assess its compatibility, and the lubrication performance of the composite system was evaluated using a four-ball friction and wear tester. The findings indicated that employing the native polymerization process (a solvent-free system) with tetramethyldihydrodisiloxane (MM^H) as a capping agent and an acidic cation-exchange resin catalyst at a dosage of 6 parts per hundred resin (phr) enabled the production of clarified and transparent target products. At a Ph/Si ratio of 1:11, F/Si of 1:36.3, and A/Si of 1:19.2, the PMPFAS demonstrated excellent thermal stability, with a 5% weight loss occurring at 394.5&#xa0;°C. The introduction of a dodecyl group improved the compatibility between the PMPFAS and the base oil. The composite system exhibited a low friction coefficient of 0.08, and the steel ball surface was smooth, with a regular and discernible abrasion pattern. These results indicate that synthetic multifunctional modified silicone oils hold significant promise as high-performance lubricants.</p>