Abstract: Smoothing agent made of by Silicone ,which had a unique structure, can give textile fabrics comfort and smoothness handle. In this experiment, it used low molecular weight hydroxy-terminated silicone oil (linear) as the main raw material, LiOH as catalyst and selected coupling agent that with different functional groups, and prepared special silicone oil in a vacuum dehydration state. Then, Polyester Filament smoothing agent was gained by emulsion. On this basis, it discussed the amino-modified silicone oil preparation, emulsifying , handle evaluation and formulation optimization in detailed. The results showed : the amino-modified polyester filament smoothing agent which was produced by amino-Content15%, molecular weight of about 50,000 silicone and composite emulsifying that used TX-3 : TX-10 = 1 : 2 had a excellent performance. Besides, we also prepared epoxy, mercapto-propyl, piperazine, urea-modified polyester filament smoothing agent, it found that the performance of amino-modified polyester filament smoothing is better than all of these.