The invention relates to a double-needle-valve electronically-controlled fuel injector with double layers of orifices and belongs to the technical field of internal combustion engines. According to the invention, the upper end of an upper body is connected with a locking nut, the lower end of the upper body is fixedly connected with the upper end of a middle body, the lower end of the middle body is connected with the upper end of the lower body; a ball valve a and an armature a are arranged in a cavity a of the upper body together; a ball valve b and an armature b are arranged in an oil return cavity a of the upper body and an oil return cavity b of the middle body together; an internal needle valve is arranged in a cavity d of an external needle valve, the internal needle valve and the external needle valve are arranged in a pressure chamber of the upper body, a cavity b of the middle body and a cavity c of the lower body together and are in sliding connection with the side wall. According to the invention, double electromagnetic valves are adopted to precisely control the injection timing of the two groups of orifices, the situation that one group of orifices is opened in low load and two groups of orifices are opened in heavy load can be realized, the requirements of different loads of the engine on the orifice number and apertures of the fuel injectors can be met, good atomizing characteristics can be achieved no matter in heavy load or low load, and relatively large fuel injection quantity can be met in heavy load, and therefore, mutual interference and overlapping of fuel sprays can be effectively avoided, and the combustion and discharge characteristic of the engine can be improved.