Abstract: Lead protection control is generally applied to long distance pipeline control system for such water hammer accidents as accidental power-cut and sudden valve shutdown. Studies accidental status of water hammer like accidental power-cut at pumping station to get optimum principle, that is maximum pipe transporting volume under new steady state and minimum integral chock pressure over entire pipeline, and then takes these as objective function. Based on steady-state and transient-state models, establishes a mathematics model of lead protection optimum case used for water hammer selection to find a solution for a lead protection optimum case with actual examples under accidental power-cut operational condition at pipeline intermediate pumping station, and makes examination to its optimization as well.