The south section of No. 11 Line of Shanghai rail transit works is a singletube doubletrack tunnel bored by 11.58 m slurry shield. Prefabricated concrete separation wall is assembled within the Metro tunnel. To this end, a separation wall assembling machine is developed on basis of the construction schedule and the working environment, so as to improve the assembly efficiency and the assembly quality. In the paper, the key technologies for the assembly of the separation wall, including the prefabricated component hoisting and assembling technology, the temporary supporting technology and the dowel steel installation technology, are presented.