Research conclusions: The research obtained that water outburst is a main engineering factor caused by soil and water losses. From current design and construction technique, this paper analyses key links and the difficulties in tunnel construction. As a result, this paper holds that advance geological exploring and hydrologic monitoring are basis of the making plan of water outburst treatment. A pre-grouting comprehensive measure that reducing water pressure upon lining is put forward，the drainage mess and drainage time length are controlled with an allowed value of water inflow and at the given period. These research results have been applied to an engineering practice of water outburst treatment in mountain tunnel of Karst zone, and it has obtained good results.