The invention provides a locomotive wheel set idling and sliding detection method and system. The method comprises, after initial alignment is performed, acquiring reference speed, reference acceleration and wheel speed output by a combined inertial navigation system, wherein the wheel speed is determined by speed pulse information collected by a speed sensor; according to the reference speed, the reference acceleration, the wheel speed and a preset formula, computing speed difference, acceleration difference and sliding rate; when the reference acceleration, the speed difference, the acceleration difference and the sliding rate meet preset idling judging conditions, determining that the operating state of a locomotive wheel set is an idling state; when the reference acceleration, the speed difference, the acceleration difference and the sliding rate meet preset sliding judging conditions, determining that the operating state of the locomotive wheel set is a sliding state. Therefore, the locomotive wheel set idling and sliding detection method achieves the effects of detecting whether the locomotive wheel set is idling or sliding to well ensure train safety.