Tube well device suitable for stratified sampling of underground water in contaminated site

The invention discloses a tube well device suitable for stratified sampling of underground water in a contaminated site. The device comprises an underground water monitoring well. The device is characterized in that a UPVC water pipe is arranged in the underground water monitoring well, the length of the UPVC water pipe is consistent with the depth of the underground water monitoring well, the UPVC water pipe is divided into an open hole section and a non-hole section, wherein the permeable layer corresponds to an open hole section, the water-resisting layer corresponds to an open hole section, an annular partition plate is arranged at the position of the water-resisting layer between the upper permeable layer and the lower permeable layer in the UPVC water pipe, and an inner pipe wall corresponding to the annular partition plate is arranged at the open hole section above the annular partition plate, so that an upper-layer water sample sampling cavity is formed between the inner pipe wall and the outer pipe w