Abstract: The fiber pre-spreading is of great importance when the continuous fiber reinforced thermoplastic resin based composites are produced by the melt impregnation process. Based on existing mechanical dispersion device and the principle of the electrostatic field force, a high voltage electrostatic field spreading device for secondary dispersion was designed. The influence of electrostatic field voltage on the pre-spreading of fiber bundle was also investigated. The results show that, under a high voltage electrostatic field, the uniformity between the fiber bundle dispersion and the fiber monofilaments is promoted, and the mechanical properties of GF/PP are improved as well. Meanwhile, the surface and interface between fiber and polymer are improved, and the fracture of fiber bundle is reduced. The experimental results show that the mechanical properties of GF/PP prepreg are optimal when the distance between the top and bottom plates is 20 cm and the voltage of static field is 30 kV.