Abstract: Points out the importance for valve room's pressure test in view of the special geological location of Beijing section in Shanjing gas pipeline; introduces the method of pressure test and purging, process and the equipment uaed for pressure test and purging applied to the three valve rooms at Beijing section 5 and points out that using the valve room structure and the equipment in it in the process of pressure test and purging will be economic and reasonable. At the same time, analyzes the reason of pressure change in valve room system during pressure stable period and points out the problem occurred in the period of valve. room's pressure test and the method to solve it.