Soil gravity water fixed-depth sampling device

The utility model belongs to the field of soil water collecting equipment, and particularly relates to a soil gravity water fixed-depth sampling device which comprises a collecting bottle, a sampler and a pressure relief hard pipe, the sampler is arranged above the collecting bottle and comprises a water containing disc, a concave-convex plate, filter cloth and a flow guide pipe, a water permeable hole is formed in the bottom of the concave-convex plate, and the pressure relief hard pipe is arranged in the water containing disc. The concave-convex plate is adaptively arranged in the water containing disc, the filter cloth is arranged above the water containing disc, the edge of the filter cloth is connected with the edge of the water containing disc, the upper port of the flow guide pipe is communicated with the bottom of the water containing disc, and the lower end of the flow guide pipe is communicated with the collecting bottle; an exhaust hole is formed in the pipe wall of the upper part of the pressure r