Small-diameter dryness sampler

The utility model relates to a small-diameter dryness sampler, which comprises a first sampling structure, a second sampling structure and a connecting cylinder. The first sampling structure comprises a first outer cylinder and a first central bar, wherein the first outer cylinder comprises an upper impact head, a first locking mechanism, a first upper sealing seat, a first sample cylinder and a first lower sealing seat, a first steam-water separator which is sheathed outside the first central bar is arranged in the first sample cylinder, and the first central bar is hermetically arranged with the first upper sealing seat and the first lower sealing seat in an axially moving way. The second sampling structure comprises a second outer cylinder and a second central bar. The second outer cylinder comprises a second upper sealing seat, a second sample cylinder, a second lower sealing seat, a second locking mechanism and a lower impact head, a second steam-water separator which is sheathed outside the second centr