The distribution of water in goaf was complicated due to gradual extension of mine level and complicated geological conditions, which brought great difficulties to excavation design and scheme determination of exploring goaf water. Therefore, how to combine this design with this scheme was the key to safe and efficient detection of water accumulation in goaf. Water detection in 21114 goaf of Dongpang mine was combined with mining design. At the same time, improvement and innovation were made for exploration scheme, which drained goaf accumulated water successfully. The result showed that this technology was an effective method to detect accumulated water in goaf quickly and efficiently under complicated geological conditions.