This paper reports an efficient solution dip coating method for the fabrication of highly transparent and conductive single-walled carbon nanotubes (SWCNTs) based thin films. The key to achieve this is properly preparing the polymer surfaces. In this paper we report a surface pretreatment approach of combining air plasma treatment and silane water solution rinsing for polyethylene terephthalate substrate. After this surface pretreatment, one dip (using a home-made dip coater) of SWCNT solution can yield a thin film of the sheet resistance less than 100 ohms/square (Omega/a-) and transparency around 90% at the wavelength of 550 nm; while two dips can produce a thin film of the sheet resistance less than 80 Omega/a- and transparency around 80% at the wavelength of 550 nm. The carbon nanotube thin film performances achieved are close to those of the ITO coatings reported in the literature and the process developed is suitable for both mass production and lab sample preparations.