As transparency of construction technology and cost of sheet pile wharf’s underground structure,competitiveness of sheet pile wharf is declined in the port construction market.Combining with 26#～27# container terminal project and previous engineering experience,we puts forward the concept of “time” and “space” in the construction process of sheet pile wharf’s underground structure.Through impact analysis on three aspects which are construction environment,process conditions,underground space disturbance,we get to the conclusion that the overall deployment of sheet pile wharf construction process is “from simple to complicated & double-line parallel construction”;we also deduce a calculation formula of trench stability under seepage action and give the safe distance of two-line parallel construction.