Six alkoxy-terminated fluorosilicone polymers (M1 ~ M4, M5, and E1) with different molecular weight and functionality were synthesized from α,ω-hydroxyl-terminated poly(methyltrifluoropropyl)siloxanes through their dehydrogenation condensation end-capping reaction with various hydrosiloxanes. The molecular structure was confirmed by FT-IR and NMR spectroscopy, and rheological methods were utilized to determine the viscosity (η) and modulus (G′ and G″) during room temperature crosslinking process. Results show that alkoxy-terminated fluorosilicone polymers own self-crosslinking property without any crosslinking agent added. When low-molecular-weight polymer M1 was selected as crosslinking agent, M4 exhibited more rapid viscosity rise and faster crosslinking rate compared with its precursor H4, and the gel time was sharply shortened from over 2h to 22.5 min. The reason is that alkoxy-termination greatly reduced the shielding effect of bulky trifluoropropyl on the reactivity of active endgroups. Fluorosilicone sealants based on M2~M4 exhibited high crosslinking density, mechanical properties, and high-and-low temperature performance.