Prevention and control of underground water harm of karst mineral deposit is always a difficult problem in the field of mine water prevention and control.However,conventional curtain grouting technology has such problems as low groundwater cut-off rate,high investment and inadequate aiming.Taking Xinqiao mine as example,the author summed up new progress of Changsha Institute of Mining Research in groundwater cut-off technology by curtain grouting,including using numerical simulating technique for optimized design and dynamical direction of curtain, and using ultrasonic perspective technique to detect permeable water passages and direct layout of grouting holes as well as using lots of modified clay slurry to control dispersion of grout.