Abstract: Taking the project of Provincial Government Station of Harbin Metro Line 2 as an example, aiming at shortcomings of the dismantling of temporary lining and laying of waterproof layer for metro station excavated by miming method at present, the technology of "one-on and two-off" and the protecting technology of waterproof layer on the construction joints at the station vault were developed. The technical problems of waterproof are solved for metro station constructed by mining method in high cold region and sand stratum with rich water, which will provide guidance for similar projects in the future.