Miniature handheld nanoscale particulate matter detection device and detection method

The invention relates to a miniature handheld nanoscale particulate matter detection device and a detection method. The device comprises an aerosol photoinduced charger, an aerosol precipitator and an aerosol mixed type condensed particle counter, the aerosol photoinduced charge device comprises a charge shell, a UVC light-emitting device and a metal electron collection net; the aerosol precipitator comprises a precipitator main body and an electric insulation spacer; the precipitator main body comprises a first metal plate, a metal disc and a second metal plate; a first gap is reserved between the first metal plate and the metal disc, and the gap and the inner wall of the electric insulation spacer form a first flowing chamber; a second gap is reserved between the second metal plate and the metal disc, and the gap and the inner wall of the electric insulation spacer form a second flowing chamber; the aerosol mixed type coagulated particle counter comprises an aerosol growth module and a photoelectric detecti