During the consolidation of the waterrich cobble ground in Nanning by means of Soletanche grouting, it is difficult to control the spreading of the grout and it is difficult to guarantee the consolidation effect. In order to solve these problems, the grouting parameters and the mixing ratio of the grout are optimized on basis of the indoor test results and the field test results, composite grout that has high antidiffusion capacity is obtained by adding additives, and slow grouting is executed under low pressure. In the end, the reliability of the grouting for the waterrich cobble ground is improved.