Abstract: The present invention relates to a stable silylated polymer emulsion and its preparation method and uses. The present emulsion comprises a silylated polymer, water, nano silica and an optional emulsifying agent. By using the preparation method of the invention, nano silica can be homogeneously dispersed in a silylated polymer. Without any surface modification, nano silica can be directly added to the silylated polymer and has good compatibility with the silylated polymer. The prepared emulsion has a solid content of <85%, a particle size of less than 3 ?m, being of a low VOC content that well meets the environmental protection requirements, and a shelf life of over half a year when stored at room temperature. After volatilization of water, the emulsion can crosslink to form an elastomer, wherein nano silica can play a role of enhancing the mechanical strength of the crosslinked polymer. In use, the emulsion can be directly diluted with water.