A device for separating, enriching and detecting ions comprises: a gas tube, in which a carrier gas flows at a uniform rate; an ion source; multiple electrodes provided in the gas tube and applied with electric voltages respectively, so that at least an electric field is produced along the axis of the gas tube; an ion detector; and an ion extraction channel, by which specific enriched ions will be guided across the side wall of the gas tube toward the ion detector and be analyzed. The device enriches ions utilizing the following characteristic: compound ions with specific ion mobility maintain a dynamic balance for a period of time in a flow field under the combination of a carrier gas and a suitable electrical field against the direction of the carrier gas. Simultaneously, multiple compound particles with different ion motilities can be separated and enriched at positions with different electrical field intensities in a flow field in the same manner. The device also comprises synchronously export latitudinally enriched ions at different positions in a flow field, and performs later mass analysis using a mass spectrometer.