The invention discloses an odor gas purification method and purification device. The purification device comprises a box, an air inlet, an air outlet, a first processing segment, a second processing segment, and a biological filter bed segment. The air inlet and the air outlet are arranged in different sides of the box. The first processing segment, the second processing segment, and the biological filter bed segment are arranged between the air inlet and the air outlet in sequence in the box. The first processing segment cools, dedusts, and oxidizes odor gas. The second processing segment humidifies, neutralizes, and absorbs odor gas. The air inlet, the first processing segment, the second processing segment, the biological filter bed segment, and the air outlet are communicated with eachother in sequence. The odor gas introduced into the device is cooled, dedusted, oxidized, neutralized, absorbed, and biologically oxidized, and the processed gas completely meets the discharge standards.