The invention discloses a construction method for an out-of-terrace slurry retaining wall reinforced concrete cast-in-place pile. The construction method comprises the steps of first, foundation leveling, second, drilling and hole clearing, third, steel sleeve installation, fourth, reinforcement cage lifting, fifth, steel sleeve fixing, sixth, concrete pouring, seventh, steel sleeve removal, and eighth, pile head maintenance. According to the construction method for the out-of-terrace slurry retaining wall reinforced concrete cast-in-place pile, a terrace at the elevation position is directlyobtained through foundation leveling, site backfilling is reduced or even eliminated when the elevation of the site terrace cannot meet the actual construction requirements, and an earthwork operationprocess is reduced; meanwhile, soil excavation between piles in a later stage is eliminated, so that the construction progress is improved; and since a pile head protrudes out from the terrace, operators can directly observe whether concrete is poured out of the pile surface in the concrete pouring construction process, so that insufficient poured concrete or ultrahigh concrete caused by underground operation and the lack of experience or operational errors of operators is avoided, the common quality problem of the pile head of the slurry retaining wall concrete cast-in-place pile is solved,and the construction speed is increased and the construction quality is improved while ensuring green construction and construction safety.