The invention relates to an ion enrichment and lead-in device for an atmospheric ion source time-of-flight mass spectrometer. The ion enrichment and lead-in device comprises an enrichment device and a repelling device, wherein ions sequentially pass through the enrichment device and the repelling device. The enrichment device comprises a closed cavity, wherein a radio-frequency four-level rod, the two ends of the radio-frequency four-level rod are provided with a first electrode with an ion inlet and a second electrode with an ion outlet, the first electrode is connected with a direct current power supply, and the second electrode is connected with a high voltage pulse power supply. The invention further relates to an ion enrichment and lead-in method. A high voltage pulse power supply is led in the second electrode, release of ions is controlled through high level and low level switching of the high voltage pulse power supply, and therefore enrichment of ions is achieved, the enrichment time and the lead-out time of ions are regulated by adjusting the pulse width, the quality detection range of an instrument is widened, and the more the enriched ions are, the higher the sensitivity of the instrument is. The device and the method can be applied to ion enrichment and lead-in of the atmospheric ion source time-of-flight mass spectrometer.