Detection unit and gas detection device

The detection unit provided by the invention comprises a detection shell, the detection unit is provided with an air chamber, the detection shell is provided with an outer surface and an inner surface, the detection shell is provided with a matching hole, the matching hole is communicated with the air chamber, the matching hole is communicated with the outside of the detection unit, the matching hole penetrates through the detection shell, and the matching hole is provided with a first opening and a second opening. The first opening is located in the outer surface, the second opening is located in the inner surface, and the first opening is smaller than the second opening. Thus, in the process that gas enters the gas chamber through the matching hole, external liquid entering the gas chamber through the matching hole can be reduced through the small-size first opening, and therefore the waterproof performance of the detection unit is improved. The invention further provides a gas detection device which compri