Research conclusions: The establishment of waterproofing and drainage system of subgrade engineering concerning ballastless track of passenger dedicated railway line has been put forward as well as four key technical problems which need to be further studied and resolved have been pointed out such as detection standard for water stability of subgrade filling, technical condition for asphalt concrete waterproof Layer of subgrade surface, subdrainage stmcture and its maintenance and system optimization of waterproofing and drainage system for subgrade.