The invention discloses a method for preparing silane modified polyether polyol having low-price and readily available raw materials and good high temperature resistance. The method is characterized by comprising the following steps of: using polyether polyol and saturated carbonic ester as raw materials; reacting the raw materials with amino alkyl alkoxy silane at the temperature of between 50 and 150 DEG C in the presence of alkali alcoholate catalyst to generate a reactant containing the silane modified polyether polyol; and performing rectification under vacuum on the reactant to obtain a high-purity product. The method is suitable for the industrial batch production of the silane modified polyether polyol.