Automatic gas distribution device without using electric control element

The utility model discloses an automatic gas distribution device without using an electric control element, which comprises a sample gas flow velocity control loop, a background gas flow velocity control loop and an output branch which are arranged in a machine body, the sample gas flow velocity control loop is sequentially provided with a sample gas access port, a sample gas flow pressure stabilizing valve, a sample gas flow velocity switching valve and a sample gas flow resistance group according to a sample gas flow direction; the background air flow speed control loop is sequentially provided with a background air access port, a background air flow pressure stabilizing valve, a background air flow speed switching valve and a background air flow air resistance group according to the background air flow direction, the sample air flow air resistance group comprises at least two sample air flow air resistors, and the background air flow air resistance group comprises at least two background air flow air resis