Silane end-capped polyurea was prepared by using polyether amine and isophorone diisocyanate as raw materials, silane coupling agent KH550 as end-capping modifier. The structure and properties of silane end-capped polyurea were characterized by FT-IR, thermogravimetric analysis, differential scanning calorimetry analysis, tensile test, water absorption rate test and water contact angle analysis. Furthermore, the influence on properties of different NCO/NH₂ mole ratio(R) was discussed. The results show that the mechanical properties, thermal stability, low temperature resistance and water resistance of polyurea are improved remarkably after end-capping modification. The tensile strength is 4.14 MPa, elongation at break is 420%, water absorption rate is 2.72% after 96 h in deionized water and the water contact angle is 78.2° when the NCO/NH₂ mole ratio is 1.05.