Disclosed is a fuel injection control system for a single-cylinder diesel engine, comprising: a set of operating condition sensors including an accelerator pedal position sensor and a cooling water temperature sensor, an input signal interface capable of receiving an input signal from the operating condition sensors, a control unit connected to the input signal interface, and a rotational speed sensor provided at a camshaft or starting shaft of the single-cylinder diesel engine. The rational speed sensor is connected to the control unit via a rotational speed correction circuit. The control system can easily and quickly determine the rotational speed and operating stroke of the single-cylinder diesel engine, so as to quickly determine the fuel injection quantity and injection timing of the single-cylinder diesel engine in real time.