The invention relates to a transparent section and a preparation process thereof. At present, plastic profiles mainly have product structures such as white, white coextrusion, color coextrusion, whole color and spray color, the conventional products do not have transparency, the lighting effect is not optimal and the manufactured doors and windows do not achieve the maximum energy-saving effect. The preparation process for the transparent section comprises the following steps of: mixing vinyl chloride resin, an organic tin stabilizer, a polyol lubricant, an internal lubricant, ultramarine blue, a release agent and a toughening agent in a proportion at 110 DEG C; when hot mixing temperature of the materials reaches 110 DEG C, performing cold mixing in a cold pot to reduce the temperature to 45 DEG C, discharging, and putting into an extruder for extrusion, wherein the processing temperature range is 170 to 210 DEG C; and performing shaping, cooling and forming by using a mold, and performing cutting and packaging to obtain the finished product. The preparation method has a simple process; and the produced transparent section has transparent whole body, good transparency and clear visual effect, effectively improves the lighting effect of doors and windows, and improves the energy-saving effect.