Abstract: A comprehensive analysis method combining pumping test and tracer test is adopted to investigate whether 73159 suspected poorly sealed borehole as artificial water conducting channel between Quaternary aquifer and mined-out area in Laogongyingzi mine. Exploratory borehole were constructed around 73159 borehole, it was analyzed whether there was obvious cone of depression of Quaternary aquifer around poorly sealed borehole by the variation characteristics of groundwater flow field in the pumping test. Potassium iodide tracer was put into borehole near the suspected poorly sealed borehole, and the trace test was conducted to test water quality characteristics of the underground outlet point. The research results show that there is no significantly decrease of S2 observation borehole next to 73159 suspected poorly sealed borehole during the pumping test, which could preliminary indicate that 73159 suspected poorly sealed borehole is not water channel between Quaternary aquifer and mined-out area. The salinity and content of Na⁺ in goaf water and Quaternary aquifer water are significantly different; the iodide concentration in goaf water adopted by the tracer test is less than 12×10^-9, which is extremely small. It shows that 73159 suspected poorly sealed borehole did not constitute a water channel to flood the Quaternary aquifer into the goaf.