The invention relates to an igniter for a motor vehicle, in particular to a digital direct-current igniter for a motorcycle. The digital direct-current igniter comprises a trigger pulse shaping circuit, a negative pulse separation circuit, a positive pulse separation circuit, an ignition advance angle control circuit, a boosting circuit taking a boosting transformer and a switch power tube as cores, and an ignition discharging circuit, and is characterized in that: the ignition advance angle control circuit takes a singlechip processor as a core; and the singlechip processor controls the boosting circuit in a pulse width modulation (PWM) mode. The ignition advance angle control circuit takes a singlechip as a control core, and the ignition advance angle of an engine is subjected to accurate curve control through the quick operation and control functions of the singlechip, so that the engine works in an optimal state; and the PWM control mode is adopted, so that constant high power is output when the boosting transformer is started, and the rise rate of charging voltage of an ignition capacitor is improved.