The invention discloses a high-efficiency air filtering unit which can detect leakages on site and disinfect in situ. The high-efficiency air filtering unit comprises a detection gasoloid generating section, a mixing section, an upstream sampling section, a high-efficiency filter pressing device, a scanning and leakage detecting device, a disinfecting device, a filter resistance monitoring device, and the like, wherein the filter pressing device adopts an eccentric pressing mechanism, and a filter replacement mode is a bag-in and bag-out mode; the scanning and leakage detecting device is an automatic scanning and leakage detecting device; and a line scanning detecting method is used as a detecting technology. The high-efficiency air filtering unit has the characteristics of good box body tightness, disinfectant corrosion resistance and safe and convenient filter replacement. The high-efficiency air filtering unit meets the requirement for biosafety, and is suitable for blowing-in and exhaust handling systems of high-grade biosafety laboratories.