Xintun Mine expansion area was the one of the most effective way to expand mine serving time, in order to guarantee the safe mining of expansion area, water-bearing stratum hydrogeological conditions in Daqing and ordovician limestone should be figured out. Water-bearing stratum hydrogeological conditions in Daqing and ordovician limestone exploration in expansion area-600 level was conducted, floor water came in 015 ordovician limestone hole construction. It was confirmed that 1 fault  exposed ordovician limestone water-bearing stratum, which caused floor water burst, through analyzing the reasons of the accident to avoid similar accidents.