Abstract: The high pressure conveyance system of Xiamen water supply project has a total length of 39. 5km, along the way, the pipes pass through a varied topography, rise and fall repeatedly. When the pump sets lose electricity during operation, for the sake of preventing pipe failure by negative pressure, installed a surge shaft at the head of the pipe line. Computed results revealed that the surge shaft can prevent occurrence of negative pressure effectively provided that adopt slowly closing pattern of the valve at pump outlet,larger positive water hammer will not take place in the pipe line, also will not result in runaway damage by reversed rotational speed.