To demolish the diaphragm wall and side wall of a complex interchange station of Metro system, we prefer to use the diamond wire saw combined with water drill rather than other methods, such as artificial chiseling, mechanical breaking and blasting, due to the high requirement on technology, environmental protection and safety risk control. We take an interchange station of newlybuilt Line 9 and exiting Line 2 of Shenzhen Metro as an example and expatiate the construction procedure of demolishing the reinforced concrete structure by means of diamond wire saw. We also discuss how to protect the operational Metro line and the newlybuilt structures. The experience we acquired in demolishing mass reinforced concrete structures with high quality and efficiency in Line 9 of Shenzhen Metro offers reference for similar projects in the future.