The east mining in China gradually came to Taiyuan lower coal seam, which causes more striking risk by Taiyuan group limestone aquifer, especially limestone aquifer in caving zone would lead to hazard in mining. Analyzing the characters of 4 and 5 limestone aquifer on 11 coal bed and comparing three different methods of advance dewatering, grouting on the ground and drilling along layer with grouting which was used, mining 11 coal bed and going through 4 and 5 limestone aquifer have accomplished after drilling along layer with grouting. Therefore, towards mining hydrogeology characteristic of a certain degree aquifer, high place permeability and full of microfissuring, drilling along layer with grouting could completely find out water passages , grouting in high pressure and filling microfissuring lead to safe mining.