Abstract: A silica aerogel-containing polyester masterbatch includes a polyethylene terephthalate resin, a silica aerogel powder, and a dispersing agent. The silica aerogel powder is dispersed in the polyethylene terephthalate resin, and is present in an amount ranging from 5 wt % to 30 wt % based on 100 wt % of the silica aerogel-containing polyester masterbatch. The dispersing agent is dispersed in the polyethylene terephthalate resin, is selected from the group consisting of a paraffin oil, a silane compound, a wax including C28-C32 straight chain monoacids, and combinations thereof, and is present in an amount ranging from 0.1 wt % to 4.0 wt % based on 100 wt % of the silica aerogel-containing polyester masterbatch. A method for preparing the silica aerogel-containing polyester masterbatch, and a silica aerogel-containing polyester fiber made from the same are also disclosed.