The invention relates to a weak leakage oil return preventing fuel injection device. The weak leakage oil return preventing fuel injection device comprises an oil injector body, a throttle orifice plate, a control valve seat, an armature, a valve core, an adjusting gasket, an armature pre-tightening spring, an electromagnet tightening cap, an electromagnet assembly, a stroke adjusting ring, a control piston, a pre-tightening spring, a transition block, an oil nozzle matching part and an oil nozzle tightening cap. The weak leakage oil return preventing fuel injection device is characterized by further comprising a sealing pad, a control disc, a control disc pre-tightening spring and an armature guide sleeve; the sealing pad is arranged on the upper portion of the valve core in a sleeving mode and located below the adjusting gasket; an annular step is arranged on a circumferential ring at the head of the control piston; the control disc pre-tightening spring is arranged on the annular step at the head of the control piston in a sleeving mode; the control disc is arranged on the upper portion of the control disc pre-tightening spring; and the upper surface of the control disc is in contact fit with the throttle orifice plate. According to the weak leakage oil return preventing fuel injection device, the problem that the sealing leakage quantity is increased due to abrasion caused by movement of a control valve can be solved; the service life of an electronic control oil injector is prolonged; and meanwhile, the oil return quantity of the electronic control oil injector is decreased, the high-pressure energy consumption loss is reduced, and the mechanical efficiency is improved.