［Objective］ To meet the protective requirements for certain engine parts that areexposed to moderate operating temperature of ≤120 ℃ for long periods，a two-component clear coating based on silicone-modified waterborne polyurethane（Si-WPU）was developed.［Methods］Si-WPU dispersion was synthesized by the prepolymer-dispersion method，and paired with a hydrophilic modified polyisocyanate curing agent. The developed dispersion was characterized by infrared spectroscopy（FT-IR）， and the synthesis mechanism of Si-WPU，the curing mechanism，and the preparation process of two-component clear coating were studied. The key properties of the coating， including heat resistance（120 ℃），wear resistance，and chemical resistance，as well as the dispersion’s stability were systematically analyzed.［Results］The results showed that the Si-WPU dispersion canbe successfully prepared and remains stable even after centrifuging at 8 000 r/min for 20 minutes. With a 33% addition of organosilicon，after long-term thermal aging at 120 ℃，the adhesion remained at grade 1，the pencil hardness was ≥H，the water absorption rate was ≤5%，and the resistance to engine oil，coolant，and other media met the actual application requirements of engine parts.［Conclusion］ This provides an environmentally friendly and efficient protective coating solution for engine parts witha maximum operating temperature of ≤120 ℃.