There are many karst areas within Wuhan-Guangzhou route. Karst grouting is one of the main construction procedures of the sub-grade construction. Through construction art tests,construction principles,water and cementation ratio,grouting construction key points and quality check requirements were determined. Grouting quantity and pressure can be determined according to different geology conditions. Recommendations for quality problems such as bad practicability of grouting,unexpected dissipation of slurry,slurry belching,and overfeeding of slurry going to non-grouting area were proposed. There are many karst areas within Wuhan-Guangzhou route. Karst grouting is one of the main construction procedures of the sub-grade construction. Through construction art tests, construction principles, water and cementation ratio, grouting construction key points and quality check requirements were determined Grouting quantity and pressure can be determined according to different geology conditions. Recommendations for quality problems such as bad practicability of grouting, unexpected dissipation of slurry, slurry belching, and overfeeding of slurry going to non-grouting area were proposed.