Abstract: The ring-opening copolymerization (ROP) of hexaethylcyclotrisiloxane (E3) and 1,3,5-trimethyl-1,3,5-tri(3,3,3-trifluoropropyl) cyclotrisiloxane (F3) was catalyzed by organic cyclotrisiloxane base (CTPB) under mild conditions. CTPB showed high catalytic activity for the polymerization of E3 and F3. Linear polydiethylsiloxanes (PDES) and poly(diethyl-ran-trifluoropropylmethyl) siloxanes (PDES-ran-PTFPMS) with different mole fractions of trifluoropropylmethyl siloxane group (F unit) (mole fraction (f_F): 0−46%) were successfully synthesized. The composition and structure of the PDES-ran-PTFPMS copolysiloxanes were characterized in detail by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR), and the glass transition temperature (T_g) and crystallization behavior of the polymers were comprehensively analyzed by differential scanning calorimetry, and the water-oil contact angle of fluorine-containing polyethylsiloxane film was investigated by microscopic contact angle test. The chemical positions of the resonance peaks in the nuclear magnetic resonance spectrum (¹H-NMR and ²⁹Si-NMR) were analyzed, indicating that the PDES-ran-PTFPMS was successfully prepared. The results of differential scanning calorimeter (DSC) indicated that the crystallization of polydiethylsiloxane at low temperature can be entirely inhibited by the introduction of F unit. The obtained PDES-ran-PTFPMS has a low glass transition temperature T_g (−134 ℃), has very excellent low temperature performance, and is an ideal precursor material for low temperature resistant rubber materials. When f_F is higher than 6.0%, the crystallization behavior was inhibited. The results of contact angle test of fluorine-containing polyethylsiloxane film demonstrated that the introduction of F unit into the PDES chain can effectively improve its hydrophobicity and decrease the oil wettability.