The invention belongs to the technical field of fuel injection systems of gasoline engines, and relates to a GDI fuel injector utilizing PTC thermal sensitive ceramic for heating. An insulation sheath, a PTC thermal sensitive ceramic pipe and a heat conduction round pipe in the GDI fuel injector sequentially wrap the outer ring of the lower portion of a needle valve, and insulation gaskets are arranged between the upper end of the PTC thermal sensitive ceramic pipe and a boss of the needle valve of the fuel injector and between the lower end of the PTC thermal sensitive ceramic pipe and the boss of the needle valve of the fuel injector respectively. The upper end of a positive wire and the upper end of a negative wire are connected with a wiring harness plug through electric conduction carbon rings and an electric conduction spring, the lower end of the positive wire and the lower end of the negative wire are connected with the positive pole and the negative pole of a heating electrode respectively, and the electric conduction carbon ring I and the electric conduction carbon ring II are connected through the electric conduction spring. The GDI fuel injector belongs to internal heating, fuel in the fuel injector can be heated to high temperature within short time, the fuel injection effect is good, the spraying effect in an air cylinder of a gasoline direct injection engine is greatly improved, cold start combustion efficiency is improved, and cold start tail gas emission is reduced. The GDI fuel injector is simple in structure, and other systems of an internal combustion engine do not need to be greatly modified.