Stratified sampling device and method of soil gas

The invention discloses a stratified sampling device and method of soil gas. The stratified sampling device comprises a gas sampling round pipe, wherein an opening is formed in the top end of the gassampling round pipe, and the bottom end of the gas sampling round pipe is sealed by a circular bottom plate; the portion, located above the middle part, of the gas sampling round pipe is divided intotwo branch pipes having semicircular cross sections by a middle vertical partition; the end portion of one branch pipe is sealed by a semicircular partition; the end portion of the vertical partitionis fixed above the semicircular partition; a first gas sampling hole is reserved in the end portion, located above the circular bottom plate, of the gas sampling round pipe; and a second gas samplinghole is reserved in the end portion, located above the semicircular partition, of the branch pipe. The sampling device is conveyed into a well, and spaces around the first gas sampling hole and the second gas sampling hole at di