In this paper,  by analysis the karst developing regulation, hydrogeological features and groundwater dynamic condition of Sifangjing karst spring, it concludes that the spring has deep relation with the sharp decline of groundwater level collapse body p building on the lugged up the groundwater runoff way caused by live main runoff zone. The sudden drying - up of Sifangjing karst caused by southwest drought in 2010 and load deep excavation construction of high-rise.