The invention relates to an underground water monitoring well and a mounting method thereof. A well body is arranged to be in the form of an inner
pipe and an outer
pipe which are coaxial, the top ofthe outer
pipe is protected and sealed through a pipe cap,
air tightness is guaranteed, a water pump acts on the top of the inner pipe, and underground water is extracted for well washing and samplingthrough a
water area of the underground water, the outer pipe and the inner pipe which are sequentially communicated in space; and fastening units are arranged between the inner pipe and the outer pipe and between the outer pipe and a
water area of underground water, and stability and smooth operation of the monitoring well are guaranteed. In the installation process, configuration and position adjustment between a
water area of underground water and the outer pipe and between the outer pipe and the inner pipe are conducted in a layer-by-layer fixing mode, and the purpose of proper installation is achieved. The water pump can be directly connected with the inner pipe, operation is easy, convenient and fast, flexibility is high, cross
contamination caused in the water taking process can beeffectively avoided,
suspended particles in pumped underground water are reduced, original functions of a traditional underground water monitoring well are not affected, extra protection is not needed, and damage is not likely to happen.